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Text file src/cmd/compile/internal/ssa/_gen/ARM64.rules

Documentation: cmd/compile/internal/ssa/_gen

     1// Copyright 2016 The Go Authors. All rights reserved.
     2// Use of this source code is governed by a BSD-style
     3// license that can be found in the LICENSE file.
     4
     5(Add(Ptr|64|32|16|8) ...) => (ADD ...)
     6(Add(32|64)F ...) => (FADD(S|D) ...)
     7
     8(Sub(Ptr|64|32|16|8) ...) => (SUB ...)
     9(Sub(32|64)F ...) => (FSUB(S|D) ...)
    10
    11(Mul64 ...) => (MUL ...)
    12(Mul(32|16|8) ...) => (MULW ...)
    13(Mul(32|64)F  ...) => (FMUL(S|D) ...)
    14
    15(Hmul64  ...) => (MULH ...)
    16(Hmul64u ...) => (UMULH ...)
    17(Hmul32  x y) => (SRAconst (MULL <typ.Int64> x y) [32])
    18(Hmul32u x y) => (SRAconst (UMULL <typ.UInt64> x y) [32])
    19(Select0 (Mul64uhilo x y)) => (UMULH x y)
    20(Select1 (Mul64uhilo x y)) => (MUL x y)
    21
    22(Div64 [false] x y) => (DIV  x y)
    23(Div32 [false] x y) => (DIVW x y)
    24(Div16 [false] x y) => (DIVW (SignExt16to32 x) (SignExt16to32 y))
    25(Div16u x y) => (UDIVW (ZeroExt16to32 x) (ZeroExt16to32 y))
    26(Div8   x y) => (DIVW  (SignExt8to32  x) (SignExt8to32  y))
    27(Div8u  x y) => (UDIVW (ZeroExt8to32  x) (ZeroExt8to32  y))
    28(Div64u ...) => (UDIV  ...)
    29(Div32u ...) => (UDIVW ...)
    30(Div32F ...) => (FDIVS ...)
    31(Div64F ...) => (FDIVD ...)
    32
    33(Mod64 x y) => (MOD x y)
    34(Mod32 x y) => (MODW x y)
    35(Mod64u ...) => (UMOD ...)
    36(Mod32u ...) => (UMODW ...)
    37(Mod(16|8)  x y) => (MODW  (SignExt(16|8)to32 x) (SignExt(16|8)to32 y))
    38(Mod(16|8)u x y) => (UMODW (ZeroExt(16|8)to32 x) (ZeroExt(16|8)to32 y))
    39
    40// (x + y) / 2 with x>=y    =>    (x - y) / 2 + y
    41(Avg64u <t> x y) => (ADD (SRLconst <t> (SUB <t> x y) [1]) y)
    42
    43(And(64|32|16|8) ...) => (AND ...)
    44(Or(64|32|16|8)  ...) => (OR ...)
    45(Xor(64|32|16|8) ...) => (XOR ...)
    46
    47// unary ops
    48(Neg(64|32|16|8) ...) => (NEG ...)
    49(Neg(32|64)F     ...) => (FNEG(S|D) ...)
    50(Com(64|32|16|8) ...) => (MVN ...)
    51
    52// math package intrinsics
    53(Abs         ...) => (FABSD   ...)
    54(Sqrt        ...) => (FSQRTD  ...)
    55(Ceil        ...) => (FRINTPD ...)
    56(Floor       ...) => (FRINTMD ...)
    57(Round       ...) => (FRINTAD ...)
    58(RoundToEven ...) => (FRINTND ...)
    59(Trunc       ...) => (FRINTZD ...)
    60(FMA       x y z) => (FMADDD z x y)
    61
    62(Sqrt32 ...) => (FSQRTS ...)
    63
    64(Min(64|32)F ...) => (FMIN(D|S) ...)
    65(Max(64|32)F ...) => (FMAX(D|S) ...)
    66
    67// lowering rotates
    68// we do rotate detection in generic rules, if the following rules need to be changed, check generic rules first.
    69(RotateLeft8  <t> x (MOVDconst [c])) => (Or8 (Lsh8x64 <t> x (MOVDconst [c&7])) (Rsh8Ux64 <t> x (MOVDconst [-c&7])))
    70(RotateLeft8  <t> x y) => (OR <t> (SLL <t> x (ANDconst <typ.Int64> [7] y)) (SRL <t> (ZeroExt8to64 x) (ANDconst <typ.Int64> [7] (NEG <typ.Int64> y))))
    71(RotateLeft16 <t> x (MOVDconst [c])) => (Or16 (Lsh16x64 <t> x (MOVDconst [c&15])) (Rsh16Ux64 <t> x (MOVDconst [-c&15])))
    72(RotateLeft16 <t> x y) => (RORW <t> (ORshiftLL <typ.UInt32> (ZeroExt16to32 x) (ZeroExt16to32 x) [16]) (NEG <typ.Int64> y))
    73(RotateLeft32 x y) => (RORW x (NEG <y.Type> y))
    74(RotateLeft64 x y) => (ROR x (NEG <y.Type> y))
    75
    76(Ctz(64|32|16|8)NonZero ...) => (Ctz(64|32|32|32) ...)
    77
    78(Ctz64 <t> x) => (CLZ  (RBIT  <t> x))
    79(Ctz32 <t> x) => (CLZW (RBITW <t> x))
    80(Ctz16 <t> x) => (CLZW <t> (RBITW <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x)))
    81(Ctz8  <t> x) => (CLZW <t> (RBITW <typ.UInt32> (ORconst <typ.UInt32> [0x100] x)))
    82
    83(PopCount64 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> x))))
    84(PopCount32 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> (ZeroExt32to64 x)))))
    85(PopCount16 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> (ZeroExt16to64 x)))))
    86
    87// Load args directly into the register class where it will be used.
    88(FMOVDgpfp <t> (Arg [off] {sym})) => @b.Func.Entry (Arg <t> [off] {sym})
    89(FMOVDfpgp <t> (Arg [off] {sym})) => @b.Func.Entry (Arg <t> [off] {sym})
    90
    91// Similarly for stores, if we see a store after FPR <=> GPR move, then redirect store to use the other register set.
    92(MOVDstore  [off] {sym} ptr (FMOVDfpgp val) mem) => (FMOVDstore [off] {sym} ptr val mem)
    93(FMOVDstore [off] {sym} ptr (FMOVDgpfp val) mem) => (MOVDstore [off] {sym} ptr val mem)
    94(MOVWstore  [off] {sym} ptr (FMOVSfpgp val) mem) => (FMOVSstore [off] {sym} ptr val mem)
    95(FMOVSstore [off] {sym} ptr (FMOVSgpfp val) mem) => (MOVWstore [off] {sym} ptr val mem)
    96
    97// float <=> int register moves, with no conversion.
    98// These come up when compiling math.{Float64bits, Float64frombits, Float32bits, Float32frombits}.
    99(MOVDload  [off] {sym} ptr (FMOVDstore [off] {sym} ptr val _)) => (FMOVDfpgp val)
   100(FMOVDload [off] {sym} ptr (MOVDstore  [off] {sym} ptr val _)) => (FMOVDgpfp val)
   101(MOVWUload [off] {sym} ptr (FMOVSstore [off] {sym} ptr val _)) => (FMOVSfpgp val)
   102(FMOVSload [off] {sym} ptr (MOVWstore  [off] {sym} ptr val _)) => (FMOVSgpfp val)
   103
   104(BitLen64 x) => (SUB (MOVDconst [64]) (CLZ <typ.Int> x))
   105(BitLen32 x) => (SUB (MOVDconst [32]) (CLZW <typ.Int> x))
   106(BitLen(16|8) x) => (BitLen64 (ZeroExt(16|8)to64 x))
   107
   108(Bswap64 ...) => (REV ...)
   109(Bswap32 ...) => (REVW ...)
   110(Bswap16 ...) => (REV16W ...)
   111
   112(BitRev64 ...) => (RBIT ...)
   113(BitRev32 ...) => (RBITW ...)
   114(BitRev16   x) => (SRLconst [48] (RBIT <typ.UInt64> x))
   115(BitRev8    x) => (SRLconst [56] (RBIT <typ.UInt64> x))
   116
   117// In fact, UMOD will be translated into UREM instruction, and UREM is originally translated into
   118// UDIV and MSUB instructions. But if there is already an identical UDIV instruction just before or
   119// after UREM (case like quo, rem := z/y, z%y), then the second UDIV instruction becomes redundant.
   120// The purpose of this rule is to have this extra UDIV instruction removed in CSE pass.
   121(UMOD  <typ.UInt64> x y) => (MSUB <typ.UInt64> x y (UDIV <typ.UInt64> x y))
   122(UMODW <typ.UInt32> x y) => (MSUBW <typ.UInt32> x y (UDIVW <typ.UInt32> x y))
   123
   124// 64-bit addition with carry.
   125(Select0 (Add64carry x y c)) => (Select0 <typ.UInt64> (ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] c))))
   126(Select1 (Add64carry x y c)) => (ADCzerocarry <typ.UInt64> (Select1 <types.TypeFlags> (ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] c)))))
   127
   128// 64-bit subtraction with borrowing.
   129(Select0 (Sub64borrow x y bo)) => (Select0 <typ.UInt64> (SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags bo))))
   130(Select1 (Sub64borrow x y bo)) => (NEG <typ.UInt64> (NGCzerocarry <typ.UInt64> (Select1 <types.TypeFlags> (SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags bo))))))
   131
   132// boolean ops -- booleans are represented with 0=false, 1=true
   133(AndB ...) => (AND ...)
   134(OrB  ...) => (OR ...)
   135(EqB  x y) => (XOR (MOVDconst [1]) (XOR <typ.Bool> x y))
   136(NeqB ...) => (XOR ...)
   137(Not    x) => (XOR (MOVDconst [1]) x)
   138
   139// shifts
   140// hardware instruction uses only the low 6 bits of the shift
   141// we compare to 64 to ensure Go semantics for large shifts
   142// Rules about rotates with non-const shift are based on the following rules,
   143// if the following rules change, please also modify the rules based on them.
   144
   145// check shiftIsBounded first, if shift value is proved to be valid then we
   146// can do the shift directly.
   147// left shift
   148(Lsh(64|32|16|8)x64 <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   149(Lsh(64|32|16|8)x32 <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   150(Lsh(64|32|16|8)x16 <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   151(Lsh(64|32|16|8)x8  <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   152
   153// signed right shift
   154(Rsh64x(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRA <t> x y)
   155(Rsh32x(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRA <t> (SignExt32to64 x) y)
   156(Rsh16x(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRA <t> (SignExt16to64 x) y)
   157(Rsh8x(64|32|16|8)  <t> x y) && shiftIsBounded(v) => (SRA <t> (SignExt8to64 x) y)
   158
   159// unsigned right shift
   160(Rsh64Ux(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRL <t> x y)
   161(Rsh32Ux(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRL <t> (ZeroExt32to64 x) y)
   162(Rsh16Ux(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRL <t> (ZeroExt16to64 x) y)
   163(Rsh8Ux(64|32|16|8)  <t> x y) && shiftIsBounded(v) => (SRL <t> (ZeroExt8to64 x) y)
   164
   165// shift value may be out of range, use CMP + CSEL instead
   166(Lsh64x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   167(Lsh64x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   168
   169(Lsh32x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   170(Lsh32x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   171
   172(Lsh16x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   173(Lsh16x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   174
   175(Lsh8x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   176(Lsh8x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   177
   178(Rsh64Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   179(Rsh64Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   180
   181(Rsh32Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt32to64 x) y) (Const64 <t> [0]) (CMPconst [64] y))
   182(Rsh32Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt32to64 x) y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   183
   184(Rsh16Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt16to64 x) y) (Const64 <t> [0]) (CMPconst [64] y))
   185(Rsh16Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt16to64 x) y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   186
   187(Rsh8Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt8to64 x) y) (Const64 <t> [0]) (CMPconst [64] y))
   188(Rsh8Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt8to64 x) y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   189
   190(Rsh64x64 x y) && !shiftIsBounded(v)        => (SRA x (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   191(Rsh64x(32|16|8) x y) && !shiftIsBounded(v) => (SRA x (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   192
   193(Rsh32x64 x y) && !shiftIsBounded(v)        => (SRA (SignExt32to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   194(Rsh32x(32|16|8) x y) && !shiftIsBounded(v) => (SRA (SignExt32to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   195
   196(Rsh16x64 x y) && !shiftIsBounded(v)        => (SRA (SignExt16to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   197(Rsh16x(32|16|8) x y) && !shiftIsBounded(v) => (SRA (SignExt16to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   198
   199(Rsh8x64 x y) && !shiftIsBounded(v)        => (SRA (SignExt8to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   200(Rsh8x(32|16|8) x y) && !shiftIsBounded(v) => (SRA (SignExt8to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   201
   202// constants
   203(Const(64|32|16|8) [val]) => (MOVDconst [int64(val)])
   204(Const(32|64)F    [val]) => (FMOV(S|D)const [float64(val)])
   205(ConstNil) => (MOVDconst [0])
   206(ConstBool [t]) => (MOVDconst [b2i(t)])
   207
   208(Slicemask <t> x) => (SRAconst (NEG <t> x) [63])
   209
   210// truncations
   211// Because we ignore high parts of registers, truncates are just copies.
   212(Trunc16to8  ...) => (Copy ...)
   213(Trunc32to8  ...) => (Copy ...)
   214(Trunc32to16 ...) => (Copy ...)
   215(Trunc64to8  ...) => (Copy ...)
   216(Trunc64to16 ...) => (Copy ...)
   217(Trunc64to32 ...) => (Copy ...)
   218
   219// Zero-/Sign-extensions
   220(ZeroExt8to16  ...) => (MOVBUreg ...)
   221(ZeroExt8to32  ...) => (MOVBUreg ...)
   222(ZeroExt16to32 ...) => (MOVHUreg ...)
   223(ZeroExt8to64  ...) => (MOVBUreg ...)
   224(ZeroExt16to64 ...) => (MOVHUreg ...)
   225(ZeroExt32to64 ...) => (MOVWUreg ...)
   226
   227(SignExt8to16  ...) => (MOVBreg ...)
   228(SignExt8to32  ...) => (MOVBreg ...)
   229(SignExt16to32 ...) => (MOVHreg ...)
   230(SignExt8to64  ...) => (MOVBreg ...)
   231(SignExt16to64 ...) => (MOVHreg ...)
   232(SignExt32to64 ...) => (MOVWreg ...)
   233
   234// float <=> int conversion
   235(Cvt32to32F  ...) => (SCVTFWS ...)
   236(Cvt32to64F  ...) => (SCVTFWD ...)
   237(Cvt64to32F  ...) => (SCVTFS ...)
   238(Cvt64to64F  ...) => (SCVTFD ...)
   239(Cvt32Uto32F ...) => (UCVTFWS ...)
   240(Cvt32Uto64F ...) => (UCVTFWD ...)
   241(Cvt64Uto32F ...) => (UCVTFS ...)
   242(Cvt64Uto64F ...) => (UCVTFD ...)
   243(Cvt32Fto32  ...) => (FCVTZSSW ...)
   244(Cvt64Fto32  ...) => (FCVTZSDW ...)
   245(Cvt32Fto64  ...) => (FCVTZSS ...)
   246(Cvt64Fto64  ...) => (FCVTZSD ...)
   247(Cvt32Fto32U ...) => (FCVTZUSW ...)
   248(Cvt64Fto32U ...) => (FCVTZUDW ...)
   249(Cvt32Fto64U ...) => (FCVTZUS ...)
   250(Cvt64Fto64U ...) => (FCVTZUD ...)
   251(Cvt32Fto64F ...) => (FCVTSD ...)
   252(Cvt64Fto32F ...) => (FCVTDS ...)
   253
   254(CvtBoolToUint8 ...) => (Copy ...)
   255
   256(Round32F ...) => (LoweredRound32F ...)
   257(Round64F ...) => (LoweredRound64F ...)
   258
   259// comparisons
   260(Eq8  x y)  => (Equal (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   261(Eq16  x y) => (Equal (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   262(Eq32  x y) => (Equal (CMPW  x y))
   263(Eq64  x y) => (Equal (CMP   x y))
   264(EqPtr x y) => (Equal (CMP   x y))
   265(Eq32F x y) => (Equal (FCMPS x y))
   266(Eq64F x y) => (Equal (FCMPD x y))
   267
   268(Neq8   x y) => (NotEqual (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   269(Neq16  x y) => (NotEqual (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   270(Neq32  x y) => (NotEqual (CMPW  x y))
   271(Neq64  x y) => (NotEqual (CMP   x y))
   272(NeqPtr x y) => (NotEqual (CMP   x y))
   273(Neq(32|64)F x y) => (NotEqual (FCMP(S|D) x y))
   274
   275(Less(8|16) x y) => (LessThan (CMPW (SignExt(8|16)to32 x) (SignExt(8|16)to32 y)))
   276(Less32 x y) => (LessThan (CMPW x y))
   277(Less64 x y) => (LessThan (CMP  x y))
   278
   279// Set condition flags for floating-point comparisons "x < y"
   280// and "x <= y". Because if either or both of the operands are
   281// NaNs, all three of (x < y), (x == y) and (x > y) are false,
   282// and ARM Manual says FCMP instruction sets PSTATE.<N,Z,C,V>
   283// of this case to (0, 0, 1, 1).
   284(Less32F x y) => (LessThanF (FCMPS x y))
   285(Less64F x y) => (LessThanF (FCMPD x y))
   286
   287// For an unsigned integer x, the following rules are useful when combining branch
   288// 0 <  x  =>  x != 0
   289// x <= 0  =>  x == 0
   290// x <  1  =>  x == 0
   291// 1 <= x  =>  x != 0
   292(Less(8U|16U|32U|64U) zero:(MOVDconst [0]) x) => (Neq(8|16|32|64) zero x)
   293(Leq(8U|16U|32U|64U)  x zero:(MOVDconst [0])) => (Eq(8|16|32|64)  x zero)
   294(Less(8U|16U|32U|64U) x (MOVDconst [1])) => (Eq(8|16|32|64)  x (MOVDconst [0]))
   295(Leq(8U|16U|32U|64U)  (MOVDconst [1]) x) => (Neq(8|16|32|64) (MOVDconst [0]) x)
   296
   297(Less8U  x y) => (LessThanU (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   298(Less16U x y) => (LessThanU (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   299(Less32U x y) => (LessThanU (CMPW x y))
   300(Less64U x y) => (LessThanU (CMP x y))
   301
   302(Leq8  x y) => (LessEqual (CMPW (SignExt8to32  x) (SignExt8to32  y)))
   303(Leq16 x y) => (LessEqual (CMPW (SignExt16to32 x) (SignExt16to32 y)))
   304(Leq32 x y) => (LessEqual (CMPW x y))
   305(Leq64 x y) => (LessEqual (CMP x y))
   306
   307// Refer to the comments for op Less64F above.
   308(Leq32F x y) => (LessEqualF (FCMPS x y))
   309(Leq64F x y) => (LessEqualF (FCMPD x y))
   310
   311(Leq8U  x y) => (LessEqualU (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   312(Leq16U x y) => (LessEqualU (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   313(Leq32U x y) => (LessEqualU (CMPW x y))
   314(Leq64U x y) => (LessEqualU (CMP x y))
   315
   316// Optimize comparison between a floating-point value and 0.0 with "FCMP $(0.0), Fn"
   317(FCMPS x (FMOVSconst [0])) => (FCMPS0 x)
   318(FCMPS (FMOVSconst [0]) x) => (InvertFlags (FCMPS0 x))
   319(FCMPD x (FMOVDconst [0])) => (FCMPD0 x)
   320(FCMPD (FMOVDconst [0]) x) => (InvertFlags (FCMPD0 x))
   321
   322// CSEL needs a flag-generating argument. Synthesize a TSTW if necessary.
   323(CondSelect x y boolval) && flagArg(boolval) != nil => (CSEL [boolval.Op] x y flagArg(boolval))
   324(CondSelect x y boolval) && flagArg(boolval) == nil => (CSEL [OpARM64NotEqual] x y (TSTWconst [1] boolval))
   325
   326(OffPtr [off] ptr:(SP)) && is32Bit(off) => (MOVDaddr [int32(off)] ptr)
   327(OffPtr [off] ptr) => (ADDconst [off] ptr)
   328
   329(Addr {sym} base) => (MOVDaddr {sym} base)
   330(LocalAddr <t> {sym} base mem) && t.Elem().HasPointers() => (MOVDaddr {sym} (SPanchored base mem))
   331(LocalAddr <t> {sym} base _)  && !t.Elem().HasPointers() => (MOVDaddr {sym} base)
   332
   333// loads
   334(Load <t> ptr mem) && t.IsBoolean() => (MOVBUload ptr mem)
   335(Load <t> ptr mem) && (is8BitInt(t)  &&  t.IsSigned()) => (MOVBload ptr mem)
   336(Load <t> ptr mem) && (is8BitInt(t)  && !t.IsSigned()) => (MOVBUload ptr mem)
   337(Load <t> ptr mem) && (is16BitInt(t) &&  t.IsSigned()) => (MOVHload ptr mem)
   338(Load <t> ptr mem) && (is16BitInt(t) && !t.IsSigned()) => (MOVHUload ptr mem)
   339(Load <t> ptr mem) && (is32BitInt(t) &&  t.IsSigned()) => (MOVWload ptr mem)
   340(Load <t> ptr mem) && (is32BitInt(t) && !t.IsSigned()) => (MOVWUload ptr mem)
   341(Load <t> ptr mem) && (is64BitInt(t) || isPtr(t)) => (MOVDload ptr mem)
   342(Load <t> ptr mem) && is32BitFloat(t) => (FMOVSload ptr mem)
   343(Load <t> ptr mem) && is64BitFloat(t) => (FMOVDload ptr mem)
   344
   345// stores
   346(Store {t} ptr val mem) && t.Size() == 1 => (MOVBstore ptr val mem)
   347(Store {t} ptr val mem) && t.Size() == 2 => (MOVHstore ptr val mem)
   348(Store {t} ptr val mem) && t.Size() == 4 && !t.IsFloat() => (MOVWstore ptr val mem)
   349(Store {t} ptr val mem) && t.Size() == 8 && !t.IsFloat() => (MOVDstore ptr val mem)
   350(Store {t} ptr val mem) && t.Size() == 4 &&  t.IsFloat() => (FMOVSstore ptr val mem)
   351(Store {t} ptr val mem) && t.Size() == 8 &&  t.IsFloat() => (FMOVDstore ptr val mem)
   352
   353// zeroing
   354(Zero [0] _   mem) => mem
   355(Zero [1] ptr mem) => (MOVBstore ptr (MOVDconst [0]) mem)
   356(Zero [2] ptr mem) => (MOVHstore ptr (MOVDconst [0]) mem)
   357(Zero [4] ptr mem) => (MOVWstore ptr (MOVDconst [0]) mem)
   358(Zero [3] ptr mem) =>
   359	(MOVBstore [2] ptr (MOVDconst [0])
   360		(MOVHstore ptr (MOVDconst [0]) mem))
   361(Zero [5] ptr mem) =>
   362	(MOVBstore [4] ptr (MOVDconst [0])
   363		(MOVWstore ptr (MOVDconst [0]) mem))
   364(Zero [6] ptr mem) =>
   365	(MOVHstore [4] ptr (MOVDconst [0])
   366		(MOVWstore ptr (MOVDconst [0]) mem))
   367(Zero [7] ptr mem) =>
   368	(MOVWstore [3] ptr (MOVDconst [0])
   369		(MOVWstore ptr (MOVDconst [0]) mem))
   370(Zero [8] ptr mem) => (MOVDstore ptr (MOVDconst [0]) mem)
   371(Zero [9] ptr mem) =>
   372	(MOVBstore [8] ptr (MOVDconst [0])
   373		(MOVDstore ptr (MOVDconst [0]) mem))
   374(Zero [10] ptr mem) =>
   375	(MOVHstore [8] ptr (MOVDconst [0])
   376		(MOVDstore ptr (MOVDconst [0]) mem))
   377(Zero [11] ptr mem) =>
   378	(MOVDstore [3] ptr (MOVDconst [0])
   379		(MOVDstore ptr (MOVDconst [0]) mem))
   380(Zero [12] ptr mem) =>
   381	(MOVWstore [8] ptr (MOVDconst [0])
   382		(MOVDstore ptr (MOVDconst [0]) mem))
   383(Zero [13] ptr mem) =>
   384	(MOVDstore [5] ptr (MOVDconst [0])
   385		(MOVDstore ptr (MOVDconst [0]) mem))
   386(Zero [14] ptr mem) =>
   387	(MOVDstore [6] ptr (MOVDconst [0])
   388		(MOVDstore ptr (MOVDconst [0]) mem))
   389(Zero [15] ptr mem) =>
   390	(MOVDstore [7] ptr (MOVDconst [0])
   391		(MOVDstore ptr (MOVDconst [0]) mem))
   392(Zero [16] ptr mem) =>
   393	(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem)
   394
   395(Zero [32] ptr mem) =>
   396	(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
   397		(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem))
   398
   399(Zero [48] ptr mem) =>
   400	(STP [32] ptr (MOVDconst [0]) (MOVDconst [0])
   401		(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
   402			(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem)))
   403
   404(Zero [64] ptr mem) =>
   405	(STP [48] ptr (MOVDconst [0]) (MOVDconst [0])
   406		(STP [32] ptr (MOVDconst [0]) (MOVDconst [0])
   407			(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
   408				(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem))))
   409
   410// strip off fractional word zeroing
   411(Zero [s] ptr mem) && s%16 != 0 && s%16 <= 8 && s > 16 =>
   412	(Zero [8]
   413		(OffPtr <ptr.Type> ptr [s-8])
   414		(Zero [s-s%16] ptr mem))
   415(Zero [s] ptr mem) && s%16 != 0 && s%16 > 8 && s > 16 =>
   416	(Zero [16]
   417		(OffPtr <ptr.Type> ptr [s-16])
   418		(Zero [s-s%16] ptr mem))
   419
   420// medium zeroing uses a duff device
   421// 4, 16, and 64 are magic constants, see runtime/mkduff.go
   422(Zero [s] ptr mem)
   423	&& s%16 == 0 && s > 64 && s <= 16*64 =>
   424	(DUFFZERO [4 * (64 - s/16)] ptr mem)
   425
   426// large zeroing uses a loop
   427(Zero [s] ptr mem)
   428	&& s%16 == 0 && s > 16*64 =>
   429	(LoweredZero
   430		ptr
   431		(ADDconst <ptr.Type> [s-16] ptr)
   432		mem)
   433
   434// moves
   435(Move [0] _   _   mem) => mem
   436(Move [1] dst src mem) => (MOVBstore dst (MOVBUload src mem) mem)
   437(Move [2] dst src mem) => (MOVHstore dst (MOVHUload src mem) mem)
   438(Move [3] dst src mem) =>
   439	(MOVBstore [2] dst (MOVBUload [2] src mem)
   440		(MOVHstore dst (MOVHUload src mem) mem))
   441(Move [4] dst src mem) => (MOVWstore dst (MOVWUload src mem) mem)
   442(Move [5] dst src mem) =>
   443	(MOVBstore [4] dst (MOVBUload [4] src mem)
   444		(MOVWstore dst (MOVWUload src mem) mem))
   445(Move [6] dst src mem) =>
   446	(MOVHstore [4] dst (MOVHUload [4] src mem)
   447		(MOVWstore dst (MOVWUload src mem) mem))
   448(Move [7] dst src mem) =>
   449	(MOVWstore [3] dst (MOVWUload [3] src mem)
   450		(MOVWstore dst (MOVWUload src mem) mem))
   451(Move [8] dst src mem) => (MOVDstore dst (MOVDload src mem) mem)
   452(Move [9] dst src mem) =>
   453	(MOVBstore [8] dst (MOVBUload [8] src mem)
   454		(MOVDstore dst (MOVDload src mem) mem))
   455(Move [10] dst src mem) =>
   456	(MOVHstore [8] dst (MOVHUload [8] src mem)
   457		(MOVDstore dst (MOVDload src mem) mem))
   458(Move [11] dst src mem) =>
   459	(MOVDstore [3] dst (MOVDload [3] src mem)
   460		(MOVDstore dst (MOVDload src mem) mem))
   461(Move [12] dst src mem) =>
   462	(MOVWstore [8] dst (MOVWUload [8] src mem)
   463		(MOVDstore dst (MOVDload src mem) mem))
   464(Move [13] dst src mem) =>
   465	(MOVDstore [5] dst (MOVDload [5] src mem)
   466		(MOVDstore dst (MOVDload src mem) mem))
   467(Move [14] dst src mem) =>
   468	(MOVDstore [6] dst (MOVDload [6] src mem)
   469		(MOVDstore dst (MOVDload src mem) mem))
   470(Move [15] dst src mem) =>
   471	(MOVDstore [7] dst (MOVDload [7] src mem)
   472		(MOVDstore dst (MOVDload src mem) mem))
   473(Move [16] dst src mem) =>
   474	(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem)
   475
   476(Move [s] dst src mem) && s > 16 && s <= 24 =>
   477	(MOVDstore [int32(s-8)] dst (MOVDload [int32(s-8)] src mem)
   478		(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))
   479(Move [s] dst src mem) && s > 24 && s <= 32 =>
   480	(STP [int32(s-16)] dst (Select0 <typ.UInt64> (LDP [int32(s-16)] src mem)) (Select1 <typ.UInt64> (LDP [int32(s-16)] src mem))
   481		(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))
   482(Move [s] dst src mem) && s > 32 && s <= 40 =>
   483	(MOVDstore [int32(s-8)] dst (MOVDload [int32(s-8)] src mem)
   484		(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   485			(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem)))
   486(Move [s] dst src mem) && s > 40 && s <= 48 =>
   487	(STP [int32(s-16)] dst (Select0 <typ.UInt64> (LDP [int32(s-16)] src mem)) (Select1 <typ.UInt64> (LDP [int32(s-16)] src mem))
   488		(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   489			(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem)))
   490(Move [s] dst src mem) && s > 48 && s <= 56 =>
   491	(MOVDstore [int32(s-8)] dst (MOVDload [int32(s-8)] src mem)
   492		(STP [32] dst (Select0 <typ.UInt64> (LDP [32] src mem)) (Select1 <typ.UInt64> (LDP [32] src mem))
   493			(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   494				(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))))
   495(Move [s] dst src mem) && s > 56 && s <= 64 =>
   496	(STP [int32(s-16)] dst (Select0 <typ.UInt64> (LDP [int32(s-16)] src mem)) (Select1 <typ.UInt64> (LDP [int32(s-16)] src mem))
   497		(STP [32] dst (Select0 <typ.UInt64> (LDP [32] src mem)) (Select1 <typ.UInt64> (LDP [32] src mem))
   498			(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   499				(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))))
   500
   501// strip off fractional word move
   502(Move [s] dst src mem) && s%16 != 0 && s%16 <= 8 && s > 64 =>
   503	(Move [8]
   504		(OffPtr <dst.Type> dst [s-8])
   505		(OffPtr <src.Type> src [s-8])
   506		(Move [s-s%16] dst src mem))
   507(Move [s] dst src mem) && s%16 != 0 && s%16 > 8 && s > 64 =>
   508	(Move [16]
   509		(OffPtr <dst.Type> dst [s-16])
   510		(OffPtr <src.Type> src [s-16])
   511		(Move [s-s%16] dst src mem))
   512
   513// medium move uses a duff device
   514(Move [s] dst src mem)
   515	&& s > 64 && s <= 16*64 && s%16 == 0
   516	&& logLargeCopy(v, s) =>
   517	(DUFFCOPY [8 * (64 - s/16)] dst src mem)
   518// 8 is the number of bytes to encode:
   519//
   520// LDP.P   16(R16), (R26, R27)
   521// STP.P   (R26, R27), 16(R17)
   522//
   523// 64 is number of these blocks. See runtime/duff_arm64.s:duffcopy
   524
   525// large move uses a loop
   526(Move [s] dst src mem)
   527	&& s%16 == 0 && s > 16*64
   528	&& logLargeCopy(v, s) =>
   529	(LoweredMove
   530		dst
   531		src
   532		(ADDconst <src.Type> src [s-16])
   533		mem)
   534
   535// calls
   536(StaticCall  ...) => (CALLstatic  ...)
   537(ClosureCall ...) => (CALLclosure ...)
   538(InterCall   ...) => (CALLinter   ...)
   539(TailCall    ...) => (CALLtail    ...)
   540
   541// checks
   542(NilCheck ...) => (LoweredNilCheck ...)
   543(IsNonNil ptr) => (NotEqual (CMPconst [0] ptr))
   544(IsInBounds      idx len) => (LessThanU  (CMP idx len))
   545(IsSliceInBounds idx len) => (LessEqualU (CMP idx len))
   546
   547// pseudo-ops
   548(GetClosurePtr ...) => (LoweredGetClosurePtr ...)
   549(GetCallerSP   ...) => (LoweredGetCallerSP   ...)
   550(GetCallerPC   ...) => (LoweredGetCallerPC   ...)
   551
   552// Absorb pseudo-ops into blocks.
   553(If (Equal         cc) yes no) => (EQ cc yes no)
   554(If (NotEqual      cc) yes no) => (NE cc yes no)
   555(If (LessThan      cc) yes no) => (LT cc yes no)
   556(If (LessThanU     cc) yes no) => (ULT cc yes no)
   557(If (LessEqual     cc) yes no) => (LE cc yes no)
   558(If (LessEqualU    cc) yes no) => (ULE cc yes no)
   559(If (GreaterThan   cc) yes no) => (GT cc yes no)
   560(If (GreaterThanU  cc) yes no) => (UGT cc yes no)
   561(If (GreaterEqual  cc) yes no) => (GE cc yes no)
   562(If (GreaterEqualU cc) yes no) => (UGE cc yes no)
   563(If (LessThanF     cc) yes no) => (FLT cc yes no)
   564(If (LessEqualF    cc) yes no) => (FLE cc yes no)
   565(If (GreaterThanF  cc) yes no) => (FGT cc yes no)
   566(If (GreaterEqualF cc) yes no) => (FGE cc yes no)
   567
   568(If cond yes no) => (TBNZ [0] cond yes no)
   569
   570(JumpTable idx) => (JUMPTABLE {makeJumpTableSym(b)} idx (MOVDaddr <typ.Uintptr> {makeJumpTableSym(b)} (SB)))
   571
   572// atomic intrinsics
   573// Note: these ops do not accept offset.
   574(AtomicLoad8   ...) => (LDARB ...)
   575(AtomicLoad32  ...) => (LDARW ...)
   576(AtomicLoad64  ...) => (LDAR  ...)
   577(AtomicLoadPtr ...) => (LDAR  ...)
   578
   579(AtomicStore8       ...) => (STLRB ...)
   580(AtomicStore32      ...) => (STLRW ...)
   581(AtomicStore64      ...) => (STLR  ...)
   582(AtomicStorePtrNoWB ...) => (STLR  ...)
   583
   584(AtomicExchange(8|32|64)       ...) => (LoweredAtomicExchange(8|32|64) ...)
   585(AtomicAdd(32|64)            ...) => (LoweredAtomicAdd(32|64)      ...)
   586(AtomicCompareAndSwap(32|64) ...) => (LoweredAtomicCas(32|64)      ...)
   587
   588(AtomicAdd(32|64)Variant            ...) => (LoweredAtomicAdd(32|64)Variant      ...)
   589(AtomicExchange(8|32|64)Variant       ...) => (LoweredAtomicExchange(8|32|64)Variant ...)
   590(AtomicCompareAndSwap(32|64)Variant ...) => (LoweredAtomicCas(32|64)Variant      ...)
   591
   592// Return old contents.
   593(AtomicAnd(64|32|8)value            ...) => (LoweredAtomicAnd(64|32|8)            ...)
   594(AtomicOr(64|32|8)value             ...) => (LoweredAtomicOr(64|32|8)             ...)
   595(AtomicAnd(64|32|8)valueVariant     ...) => (LoweredAtomicAnd(64|32|8)Variant     ...)
   596(AtomicOr(64|32|8)valueVariant      ...) => (LoweredAtomicOr(64|32|8)Variant      ...)
   597
   598// Write barrier.
   599(WB ...) => (LoweredWB ...)
   600
   601// Publication barrier (0xe is ST option)
   602(PubBarrier mem) => (DMB [0xe] mem)
   603
   604(PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem)
   605(PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem)
   606(PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem)
   607
   608// Optimizations
   609
   610// Absorb boolean tests into block
   611(NZ (Equal         cc) yes no) => (EQ  cc yes no)
   612(NZ (NotEqual      cc) yes no) => (NE  cc yes no)
   613(NZ (LessThan      cc) yes no) => (LT  cc yes no)
   614(NZ (LessThanU     cc) yes no) => (ULT cc yes no)
   615(NZ (LessEqual     cc) yes no) => (LE  cc yes no)
   616(NZ (LessEqualU    cc) yes no) => (ULE cc yes no)
   617(NZ (GreaterThan   cc) yes no) => (GT  cc yes no)
   618(NZ (GreaterThanU  cc) yes no) => (UGT cc yes no)
   619(NZ (GreaterEqual  cc) yes no) => (GE  cc yes no)
   620(NZ (GreaterEqualU cc) yes no) => (UGE cc yes no)
   621(NZ (LessThanF     cc) yes no) => (FLT cc yes no)
   622(NZ (LessEqualF    cc) yes no) => (FLE cc yes no)
   623(NZ (GreaterThanF  cc) yes no) => (FGT cc yes no)
   624(NZ (GreaterEqualF cc) yes no) => (FGE cc yes no)
   625
   626(TBNZ [0] (Equal         cc) yes no) => (EQ  cc yes no)
   627(TBNZ [0] (NotEqual      cc) yes no) => (NE  cc yes no)
   628(TBNZ [0] (LessThan      cc) yes no) => (LT  cc yes no)
   629(TBNZ [0] (LessThanU     cc) yes no) => (ULT cc yes no)
   630(TBNZ [0] (LessEqual     cc) yes no) => (LE  cc yes no)
   631(TBNZ [0] (LessEqualU    cc) yes no) => (ULE cc yes no)
   632(TBNZ [0] (GreaterThan   cc) yes no) => (GT  cc yes no)
   633(TBNZ [0] (GreaterThanU  cc) yes no) => (UGT cc yes no)
   634(TBNZ [0] (GreaterEqual  cc) yes no) => (GE  cc yes no)
   635(TBNZ [0] (GreaterEqualU cc) yes no) => (UGE cc yes no)
   636(TBNZ [0] (LessThanF     cc) yes no) => (FLT cc yes no)
   637(TBNZ [0] (LessEqualF    cc) yes no) => (FLE cc yes no)
   638(TBNZ [0] (GreaterThanF  cc) yes no) => (FGT cc yes no)
   639(TBNZ [0] (GreaterEqualF cc) yes no) => (FGE cc yes no)
   640
   641((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(AND        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TST                x y) yes no)
   642((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] x:(ANDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TSTconst         [c] y) yes no)
   643((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(AND        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TSTW               x y) yes no)
   644((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] x:(ANDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TSTWconst [int32(c)] y) yes no)
   645
   646// For conditional instructions such as CSET, CSEL.
   647((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPconst [0]  z:(AND        x y))) && z.Uses == 1 =>
   648	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TST x y))
   649((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 =>
   650	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TSTWconst [int32(c)] y))
   651((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPWconst [0] z:(AND        x y))) && z.Uses == 1 =>
   652	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TSTW x y))
   653((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPconst [0]  x:(ANDconst [c] y))) && x.Uses == 1 =>
   654	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TSTconst [c] y))
   655
   656((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] x:(ADDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNconst         [c] y) yes no)
   657((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] x:(ADDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNWconst [int32(c)] y) yes no)
   658((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(ADD        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMN                x y) yes no)
   659((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(ADD        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNW               x y) yes no)
   660
   661// CMP(x,-y) -> CMN(x,y) is only valid for unordered comparison, if y can be -1<<63
   662((EQ|NE) (CMP x z:(NEG y)) yes no)   && z.Uses == 1 => ((EQ|NE) (CMN x y) yes no)
   663((Equal|NotEqual) (CMP x z:(NEG y))) && z.Uses == 1 => ((Equal|NotEqual) (CMN x y))
   664
   665// CMPW(x,-y) -> CMNW(x,y) is only valid for unordered comparison, if y can be -1<<31
   666((EQ|NE) (CMPW x z:(NEG y)) yes no)   && z.Uses == 1 => ((EQ|NE) (CMNW x y) yes no)
   667((Equal|NotEqual) (CMPW x z:(NEG y))) && z.Uses == 1 => ((Equal|NotEqual) (CMNW x y))
   668
   669// For conditional instructions such as CSET, CSEL.
   670// TODO: add support for LE, GT, overflow needs to be considered.
   671((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] x:(ADDconst [c] y))) && x.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNconst [c] y))
   672((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] x:(ADDconst [c] y))) && x.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNWconst [int32(c)] y))
   673((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] z:(ADD        x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMN  x y))
   674((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] z:(ADD        x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNW x y))
   675((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] z:(MADD     a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMN  a (MUL  <x.Type> x y)))
   676((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] z:(MSUB     a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMP  a (MUL  <x.Type> x y)))
   677((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] z:(MADDW    a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNW a (MULW <x.Type> x y)))
   678((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] z:(MSUBW    a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMPW a (MULW <x.Type> x y)))
   679
   680((CMPconst|CMNconst)   [c] y) && c < 0 && c != -1<<63 => ((CMNconst|CMPconst)   [-c] y)
   681((CMPWconst|CMNWconst) [c] y) && c < 0 && c != -1<<31 => ((CMNWconst|CMPWconst) [-c] y)
   682
   683((EQ|NE) (CMPconst  [0] x) yes no) => ((Z|NZ)   x yes no)
   684((EQ|NE) (CMPWconst [0] x) yes no) => ((ZW|NZW) x yes no)
   685
   686((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(MADD a x y))  yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMN  a (MUL  <x.Type> x y)) yes no)
   687((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(MSUB a x y))  yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMP  a (MUL  <x.Type> x y)) yes no)
   688((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(MADDW a x y)) yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNW a (MULW <x.Type> x y)) yes no)
   689((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(MSUBW a x y)) yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMPW a (MULW <x.Type> x y)) yes no)
   690
   691// Absorb bit-tests into block
   692(Z   (ANDconst  [c] x) yes no) && oneBit(c) => (TBZ  [int64(ntz64(c))] x yes no)
   693(NZ  (ANDconst  [c] x) yes no) && oneBit(c) => (TBNZ [int64(ntz64(c))] x yes no)
   694(ZW  (ANDconst  [c] x) yes no) && oneBit(int64(uint32(c))) => (TBZ  [int64(ntz64(int64(uint32(c))))] x yes no)
   695(NZW (ANDconst  [c] x) yes no) && oneBit(int64(uint32(c))) => (TBNZ [int64(ntz64(int64(uint32(c))))] x yes no)
   696(EQ  (TSTconst  [c] x) yes no) && oneBit(c) => (TBZ  [int64(ntz64(c))] x yes no)
   697(NE  (TSTconst  [c] x) yes no) && oneBit(c) => (TBNZ [int64(ntz64(c))] x yes no)
   698(EQ  (TSTWconst [c] x) yes no) && oneBit(int64(uint32(c))) => (TBZ  [int64(ntz64(int64(uint32(c))))] x yes no)
   699(NE  (TSTWconst [c] x) yes no) && oneBit(int64(uint32(c))) => (TBNZ [int64(ntz64(int64(uint32(c))))] x yes no)
   700
   701// Test sign-bit for signed comparisons against zero
   702(GE (CMPWconst [0] x) yes no) => (TBZ  [31] x yes no)
   703(GE (CMPconst [0] x)  yes no) => (TBZ  [63] x yes no)
   704(LT (CMPWconst [0] x) yes no) => (TBNZ [31] x yes no)
   705(LT (CMPconst [0] x)  yes no) => (TBNZ [63] x yes no)
   706
   707// fold offset into address
   708(ADDconst [off1] (MOVDaddr [off2] {sym} ptr)) && is32Bit(off1+int64(off2)) =>
   709	 (MOVDaddr [int32(off1)+off2] {sym} ptr)
   710
   711// fold address into load/store.
   712// Do not fold global variable access in -dynlink mode, where it will
   713// be rewritten to use the GOT via REGTMP, which currently cannot handle
   714// large offset.
   715(MOVBload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   716	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   717	(MOVBload [off1+int32(off2)] {sym} ptr mem)
   718(MOVBUload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   719	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   720	(MOVBUload [off1+int32(off2)] {sym} ptr mem)
   721(MOVHload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   722	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   723	(MOVHload [off1+int32(off2)] {sym} ptr mem)
   724(MOVHUload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   725	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   726	(MOVHUload [off1+int32(off2)] {sym} ptr mem)
   727(MOVWload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   728	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   729	(MOVWload [off1+int32(off2)] {sym} ptr mem)
   730(MOVWUload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   731	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   732	(MOVWUload [off1+int32(off2)] {sym} ptr mem)
   733(MOVDload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   734	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   735	(MOVDload [off1+int32(off2)] {sym} ptr mem)
   736(LDP [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   737	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   738	(LDP [off1+int32(off2)] {sym} ptr mem)
   739(FMOVSload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   740	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   741	(FMOVSload [off1+int32(off2)] {sym} ptr mem)
   742(FMOVDload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   743	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   744	(FMOVDload [off1+int32(off2)] {sym} ptr mem)
   745
   746// register indexed load
   747(MOVDload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVDloadidx ptr idx mem)
   748(MOVWUload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVWUloadidx ptr idx mem)
   749(MOVWload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVWloadidx ptr idx mem)
   750(MOVHUload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVHUloadidx ptr idx mem)
   751(MOVHload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVHloadidx ptr idx mem)
   752(MOVBUload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVBUloadidx ptr idx mem)
   753(MOVBload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVBloadidx ptr idx mem)
   754(FMOVSload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (FMOVSloadidx ptr idx mem)
   755(FMOVDload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (FMOVDloadidx ptr idx mem)
   756
   757(MOVDloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVDload  [int32(c)] ptr mem)
   758(MOVDloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVDload  [int32(c)] ptr mem)
   759(MOVWUloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVWUload [int32(c)] ptr mem)
   760(MOVWUloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVWUload [int32(c)] ptr mem)
   761(MOVWloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVWload  [int32(c)] ptr mem)
   762(MOVWloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVWload  [int32(c)] ptr mem)
   763(MOVHUloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVHUload [int32(c)] ptr mem)
   764(MOVHUloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVHUload [int32(c)] ptr mem)
   765(MOVHloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVHload  [int32(c)] ptr mem)
   766(MOVHloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVHload  [int32(c)] ptr mem)
   767(MOVBUloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVBUload [int32(c)] ptr mem)
   768(MOVBUloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVBUload [int32(c)] ptr mem)
   769(MOVBloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVBload  [int32(c)] ptr mem)
   770(MOVBloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVBload  [int32(c)] ptr mem)
   771(FMOVSloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (FMOVSload [int32(c)] ptr mem)
   772(FMOVSloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (FMOVSload [int32(c)] ptr mem)
   773(FMOVDloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (FMOVDload [int32(c)] ptr mem)
   774(FMOVDloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (FMOVDload [int32(c)] ptr mem)
   775
   776// shifted register indexed load
   777(MOVDload  [off] {sym} (ADDshiftLL [3] ptr idx) mem) && off == 0 && sym == nil => (MOVDloadidx8 ptr idx mem)
   778(MOVWUload [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (MOVWUloadidx4 ptr idx mem)
   779(MOVWload  [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (MOVWloadidx4 ptr idx mem)
   780(MOVHUload [off] {sym} (ADDshiftLL [1] ptr idx) mem) && off == 0 && sym == nil => (MOVHUloadidx2 ptr idx mem)
   781(MOVHload  [off] {sym} (ADDshiftLL [1] ptr idx) mem) && off == 0 && sym == nil => (MOVHloadidx2 ptr idx mem)
   782(MOVDloadidx  ptr (SLLconst [3] idx) mem) => (MOVDloadidx8 ptr idx mem)
   783(MOVWloadidx  ptr (SLLconst [2] idx) mem) => (MOVWloadidx4 ptr idx mem)
   784(MOVWUloadidx ptr (SLLconst [2] idx) mem) => (MOVWUloadidx4 ptr idx mem)
   785(MOVHloadidx  ptr (SLLconst [1] idx) mem) => (MOVHloadidx2 ptr idx mem)
   786(MOVHUloadidx ptr (SLLconst [1] idx) mem) => (MOVHUloadidx2 ptr idx mem)
   787(MOVHloadidx  ptr (ADD idx idx) mem) => (MOVHloadidx2 ptr idx mem)
   788(MOVHUloadidx ptr (ADD idx idx) mem) => (MOVHUloadidx2 ptr idx mem)
   789(MOVDloadidx  (SLLconst [3] idx) ptr mem) => (MOVDloadidx8 ptr idx mem)
   790(MOVWloadidx  (SLLconst [2] idx) ptr mem) => (MOVWloadidx4 ptr idx mem)
   791(MOVWUloadidx (SLLconst [2] idx) ptr mem) => (MOVWUloadidx4 ptr idx mem)
   792(MOVHloadidx  (ADD idx idx) ptr mem) => (MOVHloadidx2 ptr idx mem)
   793(MOVHUloadidx (ADD idx idx) ptr mem) => (MOVHUloadidx2 ptr idx mem)
   794(MOVDloadidx8  ptr (MOVDconst [c]) mem) && is32Bit(c<<3) => (MOVDload  [int32(c)<<3] ptr mem)
   795(MOVWUloadidx4 ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (MOVWUload [int32(c)<<2] ptr mem)
   796(MOVWloadidx4  ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (MOVWload  [int32(c)<<2] ptr mem)
   797(MOVHUloadidx2 ptr (MOVDconst [c]) mem) && is32Bit(c<<1) => (MOVHUload [int32(c)<<1] ptr mem)
   798(MOVHloadidx2  ptr (MOVDconst [c]) mem) && is32Bit(c<<1) => (MOVHload  [int32(c)<<1] ptr mem)
   799
   800(FMOVDload [off] {sym} (ADDshiftLL [3] ptr idx) mem) && off == 0 && sym == nil => (FMOVDloadidx8 ptr idx mem)
   801(FMOVSload [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (FMOVSloadidx4 ptr idx mem)
   802(FMOVDloadidx ptr (SLLconst [3] idx) mem) => (FMOVDloadidx8 ptr idx mem)
   803(FMOVSloadidx ptr (SLLconst [2] idx) mem) => (FMOVSloadidx4 ptr idx mem)
   804(FMOVDloadidx (SLLconst [3] idx) ptr mem) => (FMOVDloadidx8 ptr idx mem)
   805(FMOVSloadidx (SLLconst [2] idx) ptr mem) => (FMOVSloadidx4 ptr idx mem)
   806(FMOVDloadidx8 ptr (MOVDconst [c]) mem) && is32Bit(c<<3) => (FMOVDload ptr [int32(c)<<3] mem)
   807(FMOVSloadidx4 ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (FMOVSload ptr [int32(c)<<2] mem)
   808
   809(MOVBstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   810	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   811	(MOVBstore [off1+int32(off2)] {sym} ptr val mem)
   812(MOVHstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   813	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   814	(MOVHstore [off1+int32(off2)] {sym} ptr val mem)
   815(MOVWstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   816	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   817	(MOVWstore [off1+int32(off2)] {sym} ptr val mem)
   818(MOVDstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   819	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   820	(MOVDstore [off1+int32(off2)] {sym} ptr val mem)
   821(STP [off1] {sym} (ADDconst [off2] ptr) val1 val2 mem) && is32Bit(int64(off1)+off2)
   822	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   823	(STP [off1+int32(off2)] {sym} ptr val1 val2 mem)
   824(FMOVSstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   825	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   826	(FMOVSstore [off1+int32(off2)] {sym} ptr val mem)
   827(FMOVDstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   828	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   829	(FMOVDstore [off1+int32(off2)] {sym} ptr val mem)
   830
   831// register indexed store
   832(MOVDstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVDstoreidx ptr idx val mem)
   833(MOVWstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVWstoreidx ptr idx val mem)
   834(MOVHstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVHstoreidx ptr idx val mem)
   835(MOVBstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVBstoreidx ptr idx val mem)
   836(FMOVDstore [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (FMOVDstoreidx ptr idx val mem)
   837(FMOVSstore [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (FMOVSstoreidx ptr idx val mem)
   838(MOVDstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVDstore  [int32(c)] ptr val mem)
   839(MOVDstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVDstore  [int32(c)] idx val mem)
   840(MOVWstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVWstore  [int32(c)] ptr val mem)
   841(MOVWstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVWstore  [int32(c)] idx val mem)
   842(MOVHstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVHstore  [int32(c)] ptr val mem)
   843(MOVHstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVHstore  [int32(c)] idx val mem)
   844(MOVBstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVBstore  [int32(c)] ptr val mem)
   845(MOVBstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVBstore  [int32(c)] idx val mem)
   846(FMOVDstoreidx ptr (MOVDconst [c]) val mem) && is32Bit(c) => (FMOVDstore [int32(c)] ptr val mem)
   847(FMOVDstoreidx (MOVDconst [c]) idx val mem) && is32Bit(c) => (FMOVDstore [int32(c)] idx val mem)
   848(FMOVSstoreidx ptr (MOVDconst [c]) val mem) && is32Bit(c) => (FMOVSstore [int32(c)] ptr val mem)
   849(FMOVSstoreidx (MOVDconst [c]) idx val mem) && is32Bit(c) => (FMOVSstore [int32(c)] idx val mem)
   850
   851// shifted register indexed store
   852(MOVDstore [off] {sym} (ADDshiftLL [3] ptr idx) val mem) && off == 0 && sym == nil => (MOVDstoreidx8 ptr idx val mem)
   853(MOVWstore [off] {sym} (ADDshiftLL [2] ptr idx) val mem) && off == 0 && sym == nil => (MOVWstoreidx4 ptr idx val mem)
   854(MOVHstore [off] {sym} (ADDshiftLL [1] ptr idx) val mem) && off == 0 && sym == nil => (MOVHstoreidx2 ptr idx val mem)
   855(MOVDstoreidx  ptr (SLLconst [3] idx) val mem) => (MOVDstoreidx8 ptr idx val mem)
   856(MOVWstoreidx  ptr (SLLconst [2] idx) val mem) => (MOVWstoreidx4 ptr idx val mem)
   857(MOVHstoreidx  ptr (SLLconst [1] idx) val mem) => (MOVHstoreidx2 ptr idx val mem)
   858(MOVHstoreidx  ptr (ADD      idx idx) val mem) => (MOVHstoreidx2 ptr idx val mem)
   859(MOVDstoreidx  (SLLconst [3] idx) ptr val mem) => (MOVDstoreidx8 ptr idx val mem)
   860(MOVWstoreidx  (SLLconst [2] idx) ptr val mem) => (MOVWstoreidx4 ptr idx val mem)
   861(MOVHstoreidx  (SLLconst [1] idx) ptr val mem) => (MOVHstoreidx2 ptr idx val mem)
   862(MOVHstoreidx  (ADD      idx idx) ptr val mem) => (MOVHstoreidx2 ptr idx val mem)
   863(MOVDstoreidx8 ptr (MOVDconst [c]) val mem) && is32Bit(c<<3) => (MOVDstore [int32(c)<<3] ptr val mem)
   864(MOVWstoreidx4 ptr (MOVDconst [c]) val mem) && is32Bit(c<<2) => (MOVWstore [int32(c)<<2] ptr val mem)
   865(MOVHstoreidx2 ptr (MOVDconst [c]) val mem) && is32Bit(c<<1) => (MOVHstore [int32(c)<<1] ptr val mem)
   866
   867(FMOVDstore [off] {sym} (ADDshiftLL [3] ptr idx) val mem) && off == 0 && sym == nil => (FMOVDstoreidx8 ptr idx val mem)
   868(FMOVSstore [off] {sym} (ADDshiftLL [2] ptr idx) val mem) && off == 0 && sym == nil => (FMOVSstoreidx4 ptr idx val mem)
   869(FMOVDstoreidx ptr (SLLconst [3] idx) val mem) => (FMOVDstoreidx8 ptr idx val mem)
   870(FMOVSstoreidx ptr (SLLconst [2] idx) val mem) => (FMOVSstoreidx4 ptr idx val mem)
   871(FMOVDstoreidx (SLLconst [3] idx) ptr val mem) => (FMOVDstoreidx8 ptr idx val mem)
   872(FMOVSstoreidx (SLLconst [2] idx) ptr val mem) => (FMOVSstoreidx4 ptr idx val mem)
   873(FMOVDstoreidx8 ptr (MOVDconst [c]) val mem) && is32Bit(c<<3) => (FMOVDstore [int32(c)<<3] ptr val mem)
   874(FMOVSstoreidx4 ptr (MOVDconst [c]) val mem) && is32Bit(c<<2) => (FMOVSstore [int32(c)<<2] ptr val mem)
   875
   876(MOVBload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   877	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   878	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   879	(MOVBload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   880(MOVBUload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   881	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   882	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   883	(MOVBUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   884(MOVHload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   885	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   886	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   887	(MOVHload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   888(MOVHUload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   889	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   890	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   891	(MOVHUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   892(MOVWload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   893	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   894	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   895	(MOVWload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   896(MOVWUload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   897	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   898	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   899	(MOVWUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   900(MOVDload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   901	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   902	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   903	(MOVDload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   904(LDP [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   905	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   906	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   907	(LDP [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   908(FMOVSload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   909	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   910	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   911	(FMOVSload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   912(FMOVDload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   913	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   914	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   915	(FMOVDload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   916
   917(MOVBstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   918	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   919	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   920	(MOVBstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   921(MOVHstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   922	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   923	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   924	(MOVHstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   925(MOVWstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   926	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   927	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   928	(MOVWstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   929(MOVDstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   930	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   931	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   932	(MOVDstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   933(STP [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val1 val2 mem)
   934	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   935	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   936	(STP [off1+off2] {mergeSym(sym1,sym2)} ptr val1 val2 mem)
   937(FMOVSstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   938	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   939	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   940	(FMOVSstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   941(FMOVDstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   942	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   943	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   944	(FMOVDstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   945
   946// replace load from same location as preceding store with zero/sign extension (or copy in case of full width)
   947// these seem to have bad interaction with other rules, resulting in slower code
   948//(MOVBload  [off] {sym} ptr (MOVBstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVBreg x)
   949//(MOVBUload [off] {sym} ptr (MOVBstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVBUreg x)
   950//(MOVHload  [off] {sym} ptr (MOVHstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVHreg x)
   951//(MOVHUload [off] {sym} ptr (MOVHstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVHUreg x)
   952//(MOVWload  [off] {sym} ptr (MOVWstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVWreg x)
   953//(MOVWUload [off] {sym} ptr (MOVWstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVWUreg x)
   954//(MOVDload  [off] {sym} ptr (MOVDstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x
   955//(FMOVSload [off] {sym} ptr (FMOVSstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x
   956//(FMOVDload [off] {sym} ptr (FMOVDstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x
   957//(LDP       [off] {sym} ptr (STP      [off2] {sym2} ptr2 x y _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x y
   958
   959// don't extend before store
   960(MOVBstore [off] {sym} ptr (MOVBreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   961(MOVBstore [off] {sym} ptr (MOVBUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   962(MOVBstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   963(MOVBstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   964(MOVBstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   965(MOVBstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   966(MOVHstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
   967(MOVHstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
   968(MOVHstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
   969(MOVHstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
   970(MOVWstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVWstore [off] {sym} ptr x mem)
   971(MOVWstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVWstore [off] {sym} ptr x mem)
   972(MOVBstoreidx  ptr idx (MOVBreg  x) mem) => (MOVBstoreidx  ptr idx x mem)
   973(MOVBstoreidx  ptr idx (MOVBUreg x) mem) => (MOVBstoreidx  ptr idx x mem)
   974(MOVBstoreidx  ptr idx (MOVHreg  x) mem) => (MOVBstoreidx  ptr idx x mem)
   975(MOVBstoreidx  ptr idx (MOVHUreg x) mem) => (MOVBstoreidx  ptr idx x mem)
   976(MOVBstoreidx  ptr idx (MOVWreg  x) mem) => (MOVBstoreidx  ptr idx x mem)
   977(MOVBstoreidx  ptr idx (MOVWUreg x) mem) => (MOVBstoreidx  ptr idx x mem)
   978(MOVHstoreidx  ptr idx (MOVHreg  x) mem) => (MOVHstoreidx  ptr idx x mem)
   979(MOVHstoreidx  ptr idx (MOVHUreg x) mem) => (MOVHstoreidx  ptr idx x mem)
   980(MOVHstoreidx  ptr idx (MOVWreg  x) mem) => (MOVHstoreidx  ptr idx x mem)
   981(MOVHstoreidx  ptr idx (MOVWUreg x) mem) => (MOVHstoreidx  ptr idx x mem)
   982(MOVWstoreidx  ptr idx (MOVWreg  x) mem) => (MOVWstoreidx  ptr idx x mem)
   983(MOVWstoreidx  ptr idx (MOVWUreg x) mem) => (MOVWstoreidx  ptr idx x mem)
   984(MOVHstoreidx2 ptr idx (MOVHreg  x) mem) => (MOVHstoreidx2 ptr idx x mem)
   985(MOVHstoreidx2 ptr idx (MOVHUreg x) mem) => (MOVHstoreidx2 ptr idx x mem)
   986(MOVHstoreidx2 ptr idx (MOVWreg  x) mem) => (MOVHstoreidx2 ptr idx x mem)
   987(MOVHstoreidx2 ptr idx (MOVWUreg x) mem) => (MOVHstoreidx2 ptr idx x mem)
   988(MOVWstoreidx4 ptr idx (MOVWreg  x) mem) => (MOVWstoreidx4 ptr idx x mem)
   989(MOVWstoreidx4 ptr idx (MOVWUreg x) mem) => (MOVWstoreidx4 ptr idx x mem)
   990
   991// if a register move has only 1 use, just use the same register without emitting instruction
   992// MOVDnop doesn't emit instruction, only for ensuring the type.
   993(MOVDreg x) && x.Uses == 1 => (MOVDnop x)
   994
   995// TODO: we should be able to get rid of MOVDnop all together.
   996// But for now, this is enough to get rid of lots of them.
   997(MOVDnop (MOVDconst [c])) => (MOVDconst [c])
   998
   999// fold constant into arithmetic ops
  1000(ADD  x (MOVDconst <t> [c])) && !t.IsPtr() => (ADDconst [c] x)
  1001(SUB  x (MOVDconst [c])) => (SUBconst [c] x)
  1002(AND  x (MOVDconst [c])) => (ANDconst [c] x)
  1003(OR   x (MOVDconst [c])) => (ORconst  [c] x)
  1004(XOR  x (MOVDconst [c])) => (XORconst [c] x)
  1005(TST  x (MOVDconst [c])) => (TSTconst [c] x)
  1006(TSTW x (MOVDconst [c])) => (TSTWconst [int32(c)] x)
  1007(CMN  x (MOVDconst [c])) => (CMNconst [c] x)
  1008(CMNW x (MOVDconst [c])) => (CMNWconst [int32(c)] x)
  1009(BIC  x (MOVDconst [c])) => (ANDconst [^c] x)
  1010(EON  x (MOVDconst [c])) => (XORconst [^c] x)
  1011(ORN  x (MOVDconst [c])) => (ORconst  [^c] x)
  1012
  1013(SLL x (MOVDconst [c])) => (SLLconst x [c&63])
  1014(SRL x (MOVDconst [c])) => (SRLconst x [c&63])
  1015(SRA x (MOVDconst [c])) => (SRAconst x [c&63])
  1016(SLL x (ANDconst [63] y)) => (SLL x y)
  1017(SRL x (ANDconst [63] y)) => (SRL x y)
  1018(SRA x (ANDconst [63] y)) => (SRA x y)
  1019
  1020(CMP  x (MOVDconst [c])) => (CMPconst [c] x)
  1021(CMP  (MOVDconst [c]) x) => (InvertFlags (CMPconst [c] x))
  1022(CMPW x (MOVDconst [c])) => (CMPWconst [int32(c)] x)
  1023(CMPW (MOVDconst [c]) x) => (InvertFlags (CMPWconst [int32(c)] x))
  1024
  1025(ROR  x (MOVDconst [c])) => (RORconst x [c&63])
  1026(RORW x (MOVDconst [c])) => (RORWconst x [c&31])
  1027
  1028(ADDSflags x (MOVDconst [c]))  => (ADDSconstflags [c] x)
  1029
  1030(ADDconst [c] y) && c < 0 => (SUBconst [-c] y)
  1031
  1032// Canonicalize the order of arguments to comparisons - helps with CSE.
  1033((CMP|CMPW) x y) && canonLessThan(x,y) => (InvertFlags ((CMP|CMPW) y x))
  1034
  1035// mul-neg => mneg
  1036(NEG  (MUL  x y)) => (MNEG  x y)
  1037(NEG  (MULW x y)) && v.Type.Size() <= 4 => (MNEGW x y)
  1038(MUL  (NEG  x) y) => (MNEG  x y)
  1039(MULW (NEG  x) y) => (MNEGW x y)
  1040
  1041// madd/msub
  1042(ADD a l:(MUL  x y)) && l.Uses==1 && clobber(l) => (MADD a x y)
  1043(SUB a l:(MUL  x y)) && l.Uses==1 && clobber(l) => (MSUB a x y)
  1044(ADD a l:(MNEG x y)) && l.Uses==1 && clobber(l) => (MSUB a x y)
  1045(SUB a l:(MNEG x y)) && l.Uses==1 && clobber(l) => (MADD a x y)
  1046
  1047(ADD a l:(MULW  x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MADDW a x y)
  1048(SUB a l:(MULW  x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MSUBW a x y)
  1049(ADD a l:(MNEGW x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MSUBW a x y)
  1050(SUB a l:(MNEGW x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MADDW a x y)
  1051
  1052// madd/msub can't take constant arguments, so do a bit of reordering if a non-constant is available.
  1053// Note: don't reorder arithmetic concerning pointers, as we must ensure that
  1054// no intermediate computations are invalid pointers.
  1055(ADD <t> a p:(ADDconst [c] m:((MUL|MULW|MNEG|MNEGW) _ _))) && p.Uses==1 && m.Uses==1 && !t.IsPtrShaped() => (ADDconst [c] (ADD <v.Type> a m))
  1056(ADD <t> a p:(SUBconst [c] m:((MUL|MULW|MNEG|MNEGW) _ _))) && p.Uses==1 && m.Uses==1 && !t.IsPtrShaped() => (SUBconst [c] (ADD <v.Type> a m))
  1057(SUB <t> a p:(ADDconst [c] m:((MUL|MULW|MNEG|MNEGW) _ _))) && p.Uses==1 && m.Uses==1 && !t.IsPtrShaped() => (SUBconst [c] (SUB <v.Type> a m))
  1058(SUB <t> a p:(SUBconst [c] m:((MUL|MULW|MNEG|MNEGW) _ _))) && p.Uses==1 && m.Uses==1 && !t.IsPtrShaped() => (ADDconst [c] (SUB <v.Type> a m))
  1059
  1060// optimize ADCSflags, SBCSflags and friends
  1061(ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] (ADCzerocarry <typ.UInt64> c)))) => (ADCSflags x y c)
  1062(ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] (MOVDconst [0])))) => (ADDSflags x y)
  1063(SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags (NEG <typ.UInt64> (NGCzerocarry <typ.UInt64> bo))))) => (SBCSflags x y bo)
  1064(SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags (MOVDconst [0])))) => (SUBSflags x y)
  1065
  1066// mul by constant
  1067(MUL _ (MOVDconst [0])) => (MOVDconst [0])
  1068(MUL x (MOVDconst [1])) => x
  1069
  1070(MULW _ (MOVDconst [c])) && int32(c)==0 => (MOVDconst [0])
  1071(MULW x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg x)
  1072
  1073(MUL  x (MOVDconst [c])) && canMulStrengthReduce(config, c) => {mulStrengthReduce(v, x, c)}
  1074(MULW x (MOVDconst [c])) && v.Type.Size() <= 4 && canMulStrengthReduce32(config, int32(c)) => {mulStrengthReduce32(v, x, int32(c))}
  1075
  1076// mneg by constant
  1077(MNEG x (MOVDconst [-1])) => x
  1078(MNEG _ (MOVDconst [0])) => (MOVDconst [0])
  1079(MNEG x (MOVDconst [1])) => (NEG x)
  1080(MNEG x (MOVDconst [c])) && isPowerOfTwo(c) => (NEG (SLLconst <x.Type> [log64(c)] x))
  1081(MNEG x (MOVDconst [c])) && isPowerOfTwo(c-1) && c >= 3 => (NEG (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1082(MNEG x (MOVDconst [c])) && isPowerOfTwo(c+1) && c >= 7 => (NEG (ADDshiftLL <x.Type> (NEG <x.Type> x) x [log64(c+1)]))
  1083(MNEG x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo(c/3) => (SLLconst <x.Type> [log64(c/3)] (SUBshiftLL <x.Type> x x [2]))
  1084(MNEG x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo(c/5) => (NEG (SLLconst <x.Type> [log64(c/5)] (ADDshiftLL <x.Type> x x [2])))
  1085(MNEG x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo(c/7) => (SLLconst <x.Type> [log64(c/7)] (SUBshiftLL <x.Type> x x [3]))
  1086(MNEG x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo(c/9) => (NEG (SLLconst <x.Type> [log64(c/9)] (ADDshiftLL <x.Type> x x [3])))
  1087
  1088
  1089(MNEGW x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg x)
  1090(MNEGW _ (MOVDconst [c])) && int32(c)==0 => (MOVDconst [0])
  1091(MNEGW x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg (NEG <x.Type> x))
  1092(MNEGW x (MOVDconst [c])) && isPowerOfTwo(c) => (NEG (SLLconst <x.Type> [log64(c)] x))
  1093(MNEGW x (MOVDconst [c])) && isPowerOfTwo(c-1) && int32(c) >= 3 => (MOVWUreg (NEG <x.Type> (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1094(MNEGW x (MOVDconst [c])) && isPowerOfTwo(c+1) && int32(c) >= 7 => (MOVWUreg (NEG <x.Type> (ADDshiftLL <x.Type> (NEG <x.Type> x) x [log64(c+1)])))
  1095(MNEGW x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo(c/3) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/3)] (SUBshiftLL <x.Type> x x [2])))
  1096(MNEGW x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo(c/5) && is32Bit(c) => (MOVWUreg (NEG <x.Type> (SLLconst <x.Type> [log64(c/5)] (ADDshiftLL <x.Type> x x [2]))))
  1097(MNEGW x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo(c/7) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/7)] (SUBshiftLL <x.Type> x x [3])))
  1098(MNEGW x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo(c/9) && is32Bit(c) => (MOVWUreg (NEG <x.Type> (SLLconst <x.Type> [log64(c/9)] (ADDshiftLL <x.Type> x x [3]))))
  1099
  1100
  1101(MADD a x (MOVDconst [-1])) => (SUB a x)
  1102(MADD a _ (MOVDconst [0])) => a
  1103(MADD a x (MOVDconst [1])) => (ADD a x)
  1104(MADD a x (MOVDconst [c])) && isPowerOfTwo(c) => (ADDshiftLL a x [log64(c)])
  1105(MADD a x (MOVDconst [c])) && isPowerOfTwo(c-1) && c>=3 => (ADD a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1106(MADD a x (MOVDconst [c])) && isPowerOfTwo(c+1) && c>=7 => (SUB a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1107(MADD a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo(c/3) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1108(MADD a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo(c/5) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1109(MADD a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo(c/7) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1110(MADD a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo(c/9) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1111
  1112(MADD a (MOVDconst [-1]) x) => (SUB a x)
  1113(MADD a (MOVDconst [0]) _) => a
  1114(MADD a (MOVDconst [1]) x) => (ADD a x)
  1115(MADD a (MOVDconst [c]) x) && isPowerOfTwo(c) => (ADDshiftLL a x [log64(c)])
  1116(MADD a (MOVDconst [c]) x) && isPowerOfTwo(c-1) && c>=3 => (ADD a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1117(MADD a (MOVDconst [c]) x) && isPowerOfTwo(c+1) && c>=7 => (SUB a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1118(MADD a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo(c/3) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1119(MADD a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo(c/5) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1120(MADD a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo(c/7) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1121(MADD a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo(c/9) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1122
  1123(MADDW a x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg (SUB <a.Type> a x))
  1124(MADDW a _ (MOVDconst [c])) && int32(c)==0 => (MOVWUreg a)
  1125(MADDW a x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg (ADD <a.Type> a x))
  1126(MADDW a x (MOVDconst [c])) && isPowerOfTwo(c) => (MOVWUreg (ADDshiftLL <a.Type> a x [log64(c)]))
  1127(MADDW a x (MOVDconst [c])) && isPowerOfTwo(c-1) && int32(c)>=3 => (MOVWUreg (ADD <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1128(MADDW a x (MOVDconst [c])) && isPowerOfTwo(c+1) && int32(c)>=7 => (MOVWUreg (SUB <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1129(MADDW a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo(c/3) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1130(MADDW a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo(c/5) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1131(MADDW a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo(c/7) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1132(MADDW a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo(c/9) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1133
  1134(MADDW a (MOVDconst [c]) x) && int32(c)==-1 => (MOVWUreg (SUB <a.Type> a x))
  1135(MADDW a (MOVDconst [c]) _) && int32(c)==0 => (MOVWUreg a)
  1136(MADDW a (MOVDconst [c]) x) && int32(c)==1 => (MOVWUreg (ADD <a.Type> a x))
  1137(MADDW a (MOVDconst [c]) x) && isPowerOfTwo(c) => (MOVWUreg (ADDshiftLL <a.Type> a x [log64(c)]))
  1138(MADDW a (MOVDconst [c]) x) && isPowerOfTwo(c-1) && int32(c)>=3 => (MOVWUreg (ADD <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1139(MADDW a (MOVDconst [c]) x) && isPowerOfTwo(c+1) && int32(c)>=7 => (MOVWUreg (SUB <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1140(MADDW a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo(c/3) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1141(MADDW a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo(c/5) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1142(MADDW a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo(c/7) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1143(MADDW a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo(c/9) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1144
  1145(MSUB a x (MOVDconst [-1])) => (ADD a x)
  1146(MSUB a _ (MOVDconst [0])) => a
  1147(MSUB a x (MOVDconst [1])) => (SUB a x)
  1148(MSUB a x (MOVDconst [c])) && isPowerOfTwo(c) => (SUBshiftLL a x [log64(c)])
  1149(MSUB a x (MOVDconst [c])) && isPowerOfTwo(c-1) && c>=3 => (SUB a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1150(MSUB a x (MOVDconst [c])) && isPowerOfTwo(c+1) && c>=7 => (ADD a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1151(MSUB a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo(c/3) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1152(MSUB a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo(c/5) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1153(MSUB a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo(c/7) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1154(MSUB a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo(c/9) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1155
  1156(MSUB a (MOVDconst [-1]) x) => (ADD a x)
  1157(MSUB a (MOVDconst [0]) _) => a
  1158(MSUB a (MOVDconst [1]) x) => (SUB a x)
  1159(MSUB a (MOVDconst [c]) x) && isPowerOfTwo(c) => (SUBshiftLL a x [log64(c)])
  1160(MSUB a (MOVDconst [c]) x) && isPowerOfTwo(c-1) && c>=3 => (SUB a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1161(MSUB a (MOVDconst [c]) x) && isPowerOfTwo(c+1) && c>=7 => (ADD a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1162(MSUB a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo(c/3) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1163(MSUB a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo(c/5) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1164(MSUB a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo(c/7) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1165(MSUB a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo(c/9) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1166
  1167(MSUBW a x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg (ADD <a.Type> a x))
  1168(MSUBW a _ (MOVDconst [c])) && int32(c)==0 => (MOVWUreg a)
  1169(MSUBW a x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg (SUB <a.Type> a x))
  1170(MSUBW a x (MOVDconst [c])) && isPowerOfTwo(c) => (MOVWUreg (SUBshiftLL <a.Type> a x [log64(c)]))
  1171(MSUBW a x (MOVDconst [c])) && isPowerOfTwo(c-1) && int32(c)>=3 => (MOVWUreg (SUB <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1172(MSUBW a x (MOVDconst [c])) && isPowerOfTwo(c+1) && int32(c)>=7 => (MOVWUreg (ADD <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1173(MSUBW a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo(c/3) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1174(MSUBW a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo(c/5) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1175(MSUBW a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo(c/7) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1176(MSUBW a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo(c/9) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1177
  1178(MSUBW a (MOVDconst [c]) x) && int32(c)==-1 => (MOVWUreg (ADD <a.Type> a x))
  1179(MSUBW a (MOVDconst [c]) _) && int32(c)==0 => (MOVWUreg a)
  1180(MSUBW a (MOVDconst [c]) x) && int32(c)==1 => (MOVWUreg (SUB <a.Type> a x))
  1181(MSUBW a (MOVDconst [c]) x) && isPowerOfTwo(c) => (MOVWUreg (SUBshiftLL <a.Type> a x [log64(c)]))
  1182(MSUBW a (MOVDconst [c]) x) && isPowerOfTwo(c-1) && int32(c)>=3 => (MOVWUreg (SUB <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1183(MSUBW a (MOVDconst [c]) x) && isPowerOfTwo(c+1) && int32(c)>=7 => (MOVWUreg (ADD <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1184(MSUBW a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo(c/3) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1185(MSUBW a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo(c/5) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1186(MSUBW a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo(c/7) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1187(MSUBW a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo(c/9) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1188
  1189// div by constant
  1190(UDIV  x (MOVDconst [1])) => x
  1191(UDIV  x (MOVDconst [c])) && isPowerOfTwo(c) => (SRLconst [log64(c)] x)
  1192(UDIVW x (MOVDconst [c])) && uint32(c)==1 => (MOVWUreg x)
  1193(UDIVW x (MOVDconst [c])) && isPowerOfTwo(c) && is32Bit(c) => (SRLconst [log64(c)] (MOVWUreg <v.Type> x))
  1194(UMOD  _ (MOVDconst [1])) => (MOVDconst [0])
  1195(UMOD  x (MOVDconst [c])) && isPowerOfTwo(c) => (ANDconst [c-1] x)
  1196(UMODW _ (MOVDconst [c])) && uint32(c)==1 => (MOVDconst [0])
  1197(UMODW x (MOVDconst [c])) && isPowerOfTwo(c) && is32Bit(c) => (ANDconst [c-1] x)
  1198
  1199// generic simplifications
  1200(ADD x (NEG y)) => (SUB x y)
  1201(SUB x (NEG y)) => (ADD x y)
  1202(SUB x x) => (MOVDconst [0])
  1203(AND x x) => x
  1204(OR  x x) => x
  1205(XOR x x) => (MOVDconst [0])
  1206(BIC x x) => (MOVDconst [0])
  1207(EON x x) => (MOVDconst [-1])
  1208(ORN x x) => (MOVDconst [-1])
  1209(AND x (MVN y)) => (BIC x y)
  1210(XOR x (MVN y)) => (EON x y)
  1211(OR  x (MVN y)) => (ORN x y)
  1212(MVN (XOR x y)) => (EON x y)
  1213(NEG (SUB x y)) => (SUB y x)
  1214(NEG (NEG x)) => x
  1215
  1216(CSEL [cc] (MOVDconst [-1]) (MOVDconst [0]) flag) => (CSETM [cc] flag)
  1217(CSEL [cc] (MOVDconst [0]) (MOVDconst [-1]) flag) => (CSETM [arm64Negate(cc)] flag)
  1218(CSEL [cc] x (MOVDconst [0]) flag) => (CSEL0 [cc] x flag)
  1219(CSEL [cc] (MOVDconst [0]) y flag) => (CSEL0 [arm64Negate(cc)] y flag)
  1220(CSEL [cc] x (ADDconst [1] a) flag) => (CSINC [cc] x a flag)
  1221(CSEL [cc] (ADDconst [1] a) x flag) => (CSINC [arm64Negate(cc)] x a flag)
  1222(CSEL [cc] x (MVN a) flag) => (CSINV [cc] x a flag)
  1223(CSEL [cc] (MVN a) x flag) => (CSINV [arm64Negate(cc)] x a flag)
  1224(CSEL [cc] x (NEG a) flag) => (CSNEG [cc] x a flag)
  1225(CSEL [cc] (NEG a) x flag) => (CSNEG [arm64Negate(cc)] x a flag)
  1226
  1227(SUB x (SUB y z)) => (SUB (ADD <v.Type> x z) y)
  1228(SUB (SUB x y) z) => (SUB x (ADD <y.Type> y z))
  1229
  1230// remove redundant *const ops
  1231(ADDconst [0]  x) => x
  1232(SUBconst [0]  x) => x
  1233(ANDconst [0]  _) => (MOVDconst [0])
  1234(ANDconst [-1] x) => x
  1235(ORconst  [0]  x) => x
  1236(ORconst  [-1] _) => (MOVDconst [-1])
  1237(XORconst [0]  x) => x
  1238(XORconst [-1] x) => (MVN x)
  1239
  1240// generic constant folding
  1241(ADDconst [c] (MOVDconst [d]))  => (MOVDconst [c+d])
  1242(ADDconst [c] (ADDconst [d] x)) => (ADDconst [c+d] x)
  1243(ADDconst [c] (SUBconst [d] x)) => (ADDconst [c-d] x)
  1244(SUBconst [c] (MOVDconst [d]))  => (MOVDconst [d-c])
  1245(SUBconst [c] (SUBconst [d] x)) => (ADDconst [-c-d] x)
  1246(SUBconst [c] (ADDconst [d] x)) => (ADDconst [-c+d] x)
  1247(SLLconst [c] (MOVDconst [d]))  => (MOVDconst [d<<uint64(c)])
  1248(SRLconst [c] (MOVDconst [d]))  => (MOVDconst [int64(uint64(d)>>uint64(c))])
  1249(SRAconst [c] (MOVDconst [d]))  => (MOVDconst [d>>uint64(c)])
  1250(MUL   (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [c*d])
  1251(MNEG  (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [-c*d])
  1252(MULW  (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [int64(uint32(c*d))])
  1253(MNEGW (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [int64(uint32(-c*d))])
  1254(MADD  (MOVDconst [c]) x y) => (ADDconst [c] (MUL  <x.Type> x y))
  1255(MSUB  (MOVDconst [c]) x y) => (ADDconst [c] (MNEG <x.Type> x y))
  1256(MADD  a (MOVDconst [c]) (MOVDconst [d])) => (ADDconst [c*d] a)
  1257(MSUB  a (MOVDconst [c]) (MOVDconst [d])) => (SUBconst [c*d] a)
  1258(MADDW (MOVDconst [c]) x y) => (MOVWUreg (ADDconst <x.Type> [c] (MULW  <x.Type> x y)))
  1259(MSUBW (MOVDconst [c]) x y) => (MOVWUreg (ADDconst <x.Type> [c] (MNEGW <x.Type> x y)))
  1260(MADDW a (MOVDconst [c]) (MOVDconst [d])) => (MOVWUreg (ADDconst <a.Type> [c*d] a))
  1261(MSUBW a (MOVDconst [c]) (MOVDconst [d])) => (MOVWUreg (SUBconst <a.Type> [c*d] a))
  1262(DIV   (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [c/d])
  1263(UDIV  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint64(c)/uint64(d))])
  1264(DIVW  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(int32(c)/int32(d)))])
  1265(UDIVW (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(c)/uint32(d))])
  1266(MOD   (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [c%d])
  1267(UMOD  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint64(c)%uint64(d))])
  1268(MODW  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(int32(c)%int32(d)))])
  1269(UMODW (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(c)%uint32(d))])
  1270(ANDconst [c] (MOVDconst [d]))  => (MOVDconst [c&d])
  1271(ANDconst [c] (ANDconst [d] x)) => (ANDconst [c&d] x)
  1272(ANDconst [c] (MOVWUreg x)) => (ANDconst [c&(1<<32-1)] x)
  1273(ANDconst [c] (MOVHUreg x)) => (ANDconst [c&(1<<16-1)] x)
  1274(ANDconst [c] (MOVBUreg x)) => (ANDconst [c&(1<<8-1)] x)
  1275(MOVWUreg (ANDconst [c] x)) => (ANDconst [c&(1<<32-1)] x)
  1276(MOVHUreg (ANDconst [c] x)) => (ANDconst [c&(1<<16-1)] x)
  1277(MOVBUreg (ANDconst [c] x)) => (ANDconst [c&(1<<8-1)] x)
  1278(ORconst  [c] (MOVDconst [d]))  => (MOVDconst [c|d])
  1279(ORconst  [c] (ORconst [d] x))  => (ORconst [c|d] x)
  1280(XORconst [c] (MOVDconst [d]))  => (MOVDconst [c^d])
  1281(XORconst [c] (XORconst [d] x)) => (XORconst [c^d] x)
  1282(MVN (MOVDconst [c])) => (MOVDconst [^c])
  1283(NEG (MOVDconst [c])) => (MOVDconst [-c])
  1284(MOVBreg  (MOVDconst [c])) => (MOVDconst [int64(int8(c))])
  1285(MOVBUreg (MOVDconst [c])) => (MOVDconst [int64(uint8(c))])
  1286(MOVHreg  (MOVDconst [c])) => (MOVDconst [int64(int16(c))])
  1287(MOVHUreg (MOVDconst [c])) => (MOVDconst [int64(uint16(c))])
  1288(MOVWreg  (MOVDconst [c])) => (MOVDconst [int64(int32(c))])
  1289(MOVWUreg (MOVDconst [c])) => (MOVDconst [int64(uint32(c))])
  1290(MOVDreg  (MOVDconst [c])) => (MOVDconst [c])
  1291
  1292// constant comparisons
  1293(CMPconst  (MOVDconst [x]) [y]) => (FlagConstant [subFlags64(x,y)])
  1294(CMPWconst (MOVDconst [x]) [y]) => (FlagConstant [subFlags32(int32(x),y)])
  1295(TSTconst  (MOVDconst [x]) [y]) => (FlagConstant [logicFlags64(x&y)])
  1296(TSTWconst (MOVDconst [x]) [y]) => (FlagConstant [logicFlags32(int32(x)&y)])
  1297(CMNconst  (MOVDconst [x]) [y]) => (FlagConstant [addFlags64(x,y)])
  1298(CMNWconst (MOVDconst [x]) [y]) => (FlagConstant [addFlags32(int32(x),y)])
  1299
  1300// other known comparisons
  1301(CMPconst  (MOVBUreg _) [c]) && 0xff < c       => (FlagConstant [subFlags64(0,1)])
  1302(CMPconst  (MOVHUreg _) [c]) && 0xffff < c     => (FlagConstant [subFlags64(0,1)])
  1303(CMPconst  (MOVWUreg _) [c]) && 0xffffffff < c => (FlagConstant [subFlags64(0,1)])
  1304(CMPconst  (ANDconst _ [m]) [n]) && 0 <= m && m < n => (FlagConstant [subFlags64(0,1)])
  1305(CMPconst  (SRLconst _ [c]) [n]) && 0 <= n && 0 < c && c <= 63 && (1<<uint64(64-c)) <= uint64(n) => (FlagConstant [subFlags64(0,1)])
  1306(CMPWconst (MOVBUreg _) [c]) && 0xff   < c => (FlagConstant [subFlags64(0,1)])
  1307(CMPWconst (MOVHUreg _) [c]) && 0xffff < c => (FlagConstant [subFlags64(0,1)])
  1308
  1309// absorb flag constants into branches
  1310(EQ (FlagConstant [fc]) yes no) &&  fc.eq() => (First yes no)
  1311(EQ (FlagConstant [fc]) yes no) && !fc.eq() => (First no yes)
  1312
  1313(NE (FlagConstant [fc]) yes no) &&  fc.ne() => (First yes no)
  1314(NE (FlagConstant [fc]) yes no) && !fc.ne() => (First no yes)
  1315
  1316(LT (FlagConstant [fc]) yes no) &&  fc.lt() => (First yes no)
  1317(LT (FlagConstant [fc]) yes no) && !fc.lt() => (First no yes)
  1318
  1319(LE (FlagConstant [fc]) yes no) &&  fc.le() => (First yes no)
  1320(LE (FlagConstant [fc]) yes no) && !fc.le() => (First no yes)
  1321
  1322(GT (FlagConstant [fc]) yes no) &&  fc.gt() => (First yes no)
  1323(GT (FlagConstant [fc]) yes no) && !fc.gt() => (First no yes)
  1324
  1325(GE (FlagConstant [fc]) yes no) &&  fc.ge() => (First yes no)
  1326(GE (FlagConstant [fc]) yes no) && !fc.ge() => (First no yes)
  1327
  1328(ULT (FlagConstant [fc]) yes no) &&  fc.ult() => (First yes no)
  1329(ULT (FlagConstant [fc]) yes no) && !fc.ult() => (First no yes)
  1330
  1331(ULE (FlagConstant [fc]) yes no) &&  fc.ule() => (First yes no)
  1332(ULE (FlagConstant [fc]) yes no) && !fc.ule() => (First no yes)
  1333
  1334(UGT (FlagConstant [fc]) yes no) &&  fc.ugt() => (First yes no)
  1335(UGT (FlagConstant [fc]) yes no) && !fc.ugt() => (First no yes)
  1336
  1337(UGE (FlagConstant [fc]) yes no) &&  fc.uge() => (First yes no)
  1338(UGE (FlagConstant [fc]) yes no) && !fc.uge() => (First no yes)
  1339
  1340(LTnoov (FlagConstant [fc]) yes no) &&  fc.ltNoov() => (First yes no)
  1341(LTnoov (FlagConstant [fc]) yes no) && !fc.ltNoov() => (First no yes)
  1342
  1343(LEnoov (FlagConstant [fc]) yes no) &&  fc.leNoov() => (First yes no)
  1344(LEnoov (FlagConstant [fc]) yes no) && !fc.leNoov() => (First no yes)
  1345
  1346(GTnoov (FlagConstant [fc]) yes no) &&  fc.gtNoov() => (First yes no)
  1347(GTnoov (FlagConstant [fc]) yes no) && !fc.gtNoov() => (First no yes)
  1348
  1349(GEnoov (FlagConstant [fc]) yes no) &&  fc.geNoov() => (First yes no)
  1350(GEnoov (FlagConstant [fc]) yes no) && !fc.geNoov() => (First no yes)
  1351
  1352(Z   (MOVDconst [0]) yes no)                  => (First yes no)
  1353(Z   (MOVDconst [c]) yes no) && c != 0        => (First no yes)
  1354(NZ  (MOVDconst [0]) yes no)                  => (First no yes)
  1355(NZ  (MOVDconst [c]) yes no) && c != 0        => (First yes no)
  1356(ZW  (MOVDconst [c]) yes no) && int32(c) == 0 => (First yes no)
  1357(ZW  (MOVDconst [c]) yes no) && int32(c) != 0 => (First no yes)
  1358(NZW (MOVDconst [c]) yes no) && int32(c) == 0 => (First no yes)
  1359(NZW (MOVDconst [c]) yes no) && int32(c) != 0 => (First yes no)
  1360
  1361// absorb InvertFlags into branches
  1362(LT  (InvertFlags cmp) yes no) => (GT cmp yes no)
  1363(GT  (InvertFlags cmp) yes no) => (LT cmp yes no)
  1364(LE  (InvertFlags cmp) yes no) => (GE cmp yes no)
  1365(GE  (InvertFlags cmp) yes no) => (LE cmp yes no)
  1366(ULT (InvertFlags cmp) yes no) => (UGT cmp yes no)
  1367(UGT (InvertFlags cmp) yes no) => (ULT cmp yes no)
  1368(ULE (InvertFlags cmp) yes no) => (UGE cmp yes no)
  1369(UGE (InvertFlags cmp) yes no) => (ULE cmp yes no)
  1370(EQ  (InvertFlags cmp) yes no) => (EQ cmp yes no)
  1371(NE  (InvertFlags cmp) yes no) => (NE cmp yes no)
  1372(FLT (InvertFlags cmp) yes no) => (FGT cmp yes no)
  1373(FGT (InvertFlags cmp) yes no) => (FLT cmp yes no)
  1374(FLE (InvertFlags cmp) yes no) => (FGE cmp yes no)
  1375(FGE (InvertFlags cmp) yes no) => (FLE cmp yes no)
  1376(LTnoov (InvertFlags cmp) yes no) => (GTnoov cmp yes no)
  1377(GEnoov (InvertFlags cmp) yes no) => (LEnoov cmp yes no)
  1378(LEnoov (InvertFlags cmp) yes no) => (GEnoov cmp yes no)
  1379(GTnoov (InvertFlags cmp) yes no) => (LTnoov cmp yes no)
  1380
  1381// absorb InvertFlags into conditional instructions
  1382(CSEL  [cc] x y (InvertFlags cmp)) => (CSEL  [arm64Invert(cc)] x y cmp)
  1383(CSEL0 [cc] x   (InvertFlags cmp)) => (CSEL0 [arm64Invert(cc)] x   cmp)
  1384(CSETM [cc]     (InvertFlags cmp)) => (CSETM [arm64Invert(cc)]     cmp)
  1385(CSINC [cc] x y (InvertFlags cmp)) => (CSINC [arm64Invert(cc)] x y cmp)
  1386(CSINV [cc] x y (InvertFlags cmp)) => (CSINV [arm64Invert(cc)] x y cmp)
  1387(CSNEG [cc] x y (InvertFlags cmp)) => (CSNEG [arm64Invert(cc)] x y cmp)
  1388
  1389// absorb flag constants into boolean values
  1390(Equal             (FlagConstant [fc])) => (MOVDconst [b2i(fc.eq())])
  1391(NotEqual          (FlagConstant [fc])) => (MOVDconst [b2i(fc.ne())])
  1392(LessThan          (FlagConstant [fc])) => (MOVDconst [b2i(fc.lt())])
  1393(LessThanU         (FlagConstant [fc])) => (MOVDconst [b2i(fc.ult())])
  1394(LessEqual         (FlagConstant [fc])) => (MOVDconst [b2i(fc.le())])
  1395(LessEqualU        (FlagConstant [fc])) => (MOVDconst [b2i(fc.ule())])
  1396(GreaterThan       (FlagConstant [fc])) => (MOVDconst [b2i(fc.gt())])
  1397(GreaterThanU      (FlagConstant [fc])) => (MOVDconst [b2i(fc.ugt())])
  1398(GreaterEqual      (FlagConstant [fc])) => (MOVDconst [b2i(fc.ge())])
  1399(GreaterEqualU     (FlagConstant [fc])) => (MOVDconst [b2i(fc.uge())])
  1400(LessThanNoov      (FlagConstant [fc])) => (MOVDconst [b2i(fc.ltNoov())])
  1401(GreaterEqualNoov  (FlagConstant [fc])) => (MOVDconst [b2i(fc.geNoov())])
  1402
  1403// absorb InvertFlags into boolean values
  1404(Equal            (InvertFlags x)) => (Equal x)
  1405(NotEqual         (InvertFlags x)) => (NotEqual x)
  1406(LessThan         (InvertFlags x)) => (GreaterThan x)
  1407(LessThanU        (InvertFlags x)) => (GreaterThanU x)
  1408(GreaterThan      (InvertFlags x)) => (LessThan x)
  1409(GreaterThanU     (InvertFlags x)) => (LessThanU x)
  1410(LessEqual        (InvertFlags x)) => (GreaterEqual x)
  1411(LessEqualU       (InvertFlags x)) => (GreaterEqualU x)
  1412(GreaterEqual     (InvertFlags x)) => (LessEqual x)
  1413(GreaterEqualU    (InvertFlags x)) => (LessEqualU x)
  1414(LessThanF        (InvertFlags x)) => (GreaterThanF x)
  1415(LessEqualF       (InvertFlags x)) => (GreaterEqualF x)
  1416(GreaterThanF     (InvertFlags x)) => (LessThanF x)
  1417(GreaterEqualF    (InvertFlags x)) => (LessEqualF x)
  1418(LessThanNoov     (InvertFlags x)) => (CSEL0 [OpARM64NotEqual] (GreaterEqualNoov <typ.Bool> x) x)
  1419(GreaterEqualNoov (InvertFlags x)) => (CSINC [OpARM64NotEqual] (LessThanNoov <typ.Bool> x) (MOVDconst [0]) x)
  1420
  1421// Don't bother extending if we're not using the higher bits.
  1422(MOV(B|BU)reg x) && v.Type.Size() <= 1 => x
  1423(MOV(H|HU)reg x) && v.Type.Size() <= 2 => x
  1424(MOV(W|WU)reg x) && v.Type.Size() <= 4 => x
  1425
  1426// omit sign extension
  1427(MOVWreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffff80000000) == 0 => (ANDconst <t> x [c])
  1428(MOVHreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffffffff8000) == 0 => (ANDconst <t> x [c])
  1429(MOVBreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffffffffff80) == 0 => (ANDconst <t> x [c])
  1430
  1431// absorb flag constants into conditional instructions
  1432(CSEL  [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1433(CSEL  [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => y
  1434(CSEL0 [cc] x   flag) && ccARM64Eval(cc, flag) > 0 => x
  1435(CSEL0 [cc] _   flag) && ccARM64Eval(cc, flag) < 0 => (MOVDconst [0])
  1436(CSNEG [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1437(CSNEG [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => (NEG y)
  1438(CSINV [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1439(CSINV [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => (Not y)
  1440(CSINC [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1441(CSINC [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => (ADDconst [1] y)
  1442(CSETM [cc]     flag) && ccARM64Eval(cc, flag) > 0 => (MOVDconst [-1])
  1443(CSETM [cc]     flag) && ccARM64Eval(cc, flag) < 0 => (MOVDconst [0])
  1444
  1445// absorb flags back into boolean CSEL
  1446(CSEL [cc] x y (CMPWconst [0] boolval)) && cc == OpARM64NotEqual && flagArg(boolval) != nil =>
  1447      (CSEL [boolval.Op] x y flagArg(boolval))
  1448(CSEL [cc] x y (CMPWconst [0] boolval)) && cc == OpARM64Equal && flagArg(boolval) != nil =>
  1449      (CSEL [arm64Negate(boolval.Op)] x y flagArg(boolval))
  1450(CSEL0 [cc] x (CMPWconst [0] boolval)) && cc == OpARM64NotEqual && flagArg(boolval) != nil =>
  1451      (CSEL0 [boolval.Op] x flagArg(boolval))
  1452(CSEL0 [cc] x (CMPWconst [0] boolval)) && cc == OpARM64Equal && flagArg(boolval) != nil =>
  1453      (CSEL0 [arm64Negate(boolval.Op)] x flagArg(boolval))
  1454
  1455// absorb shifts into ops
  1456(NEG x:(SLLconst [c] y)) && clobberIfDead(x) => (NEGshiftLL [c] y)
  1457(NEG x:(SRLconst [c] y)) && clobberIfDead(x) => (NEGshiftRL [c] y)
  1458(NEG x:(SRAconst [c] y)) && clobberIfDead(x) => (NEGshiftRA [c] y)
  1459(MVN x:(SLLconst [c] y)) && clobberIfDead(x) => (MVNshiftLL [c] y)
  1460(MVN x:(SRLconst [c] y)) && clobberIfDead(x) => (MVNshiftRL [c] y)
  1461(MVN x:(SRAconst [c] y)) && clobberIfDead(x) => (MVNshiftRA [c] y)
  1462(MVN x:(RORconst [c] y)) && clobberIfDead(x) => (MVNshiftRO [c] y)
  1463(ADD x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ADDshiftLL x0 y [c])
  1464(ADD x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ADDshiftRL x0 y [c])
  1465(ADD x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ADDshiftRA x0 y [c])
  1466(SUB x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (SUBshiftLL x0 y [c])
  1467(SUB x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (SUBshiftRL x0 y [c])
  1468(SUB x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (SUBshiftRA x0 y [c])
  1469(AND x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ANDshiftLL x0 y [c])
  1470(AND x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ANDshiftRL x0 y [c])
  1471(AND x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ANDshiftRA x0 y [c])
  1472(AND x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (ANDshiftRO x0 y [c])
  1473(OR  x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ORshiftLL  x0 y [c]) // useful for combined load
  1474(OR  x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ORshiftRL  x0 y [c])
  1475(OR  x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ORshiftRA  x0 y [c])
  1476(OR  x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (ORshiftRO  x0 y [c])
  1477(XOR x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (XORshiftLL x0 y [c])
  1478(XOR x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (XORshiftRL x0 y [c])
  1479(XOR x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (XORshiftRA x0 y [c])
  1480(XOR x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (XORshiftRO x0 y [c])
  1481(BIC x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (BICshiftLL x0 y [c])
  1482(BIC x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (BICshiftRL x0 y [c])
  1483(BIC x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (BICshiftRA x0 y [c])
  1484(BIC x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (BICshiftRO x0 y [c])
  1485(ORN x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ORNshiftLL x0 y [c])
  1486(ORN x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ORNshiftRL x0 y [c])
  1487(ORN x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ORNshiftRA x0 y [c])
  1488(ORN x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (ORNshiftRO x0 y [c])
  1489(EON x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (EONshiftLL x0 y [c])
  1490(EON x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (EONshiftRL x0 y [c])
  1491(EON x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (EONshiftRA x0 y [c])
  1492(EON x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (EONshiftRO x0 y [c])
  1493(CMP x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (CMPshiftLL x0 y [c])
  1494(CMP x0:(SLLconst [c] y) x1) && clobberIfDead(x0) => (InvertFlags (CMPshiftLL x1 y [c]))
  1495(CMP x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (CMPshiftRL x0 y [c])
  1496(CMP x0:(SRLconst [c] y) x1) && clobberIfDead(x0) => (InvertFlags (CMPshiftRL x1 y [c]))
  1497(CMP x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (CMPshiftRA x0 y [c])
  1498(CMP x0:(SRAconst [c] y) x1) && clobberIfDead(x0) => (InvertFlags (CMPshiftRA x1 y [c]))
  1499(CMN x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (CMNshiftLL x0 y [c])
  1500(CMN x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (CMNshiftRL x0 y [c])
  1501(CMN x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (CMNshiftRA x0 y [c])
  1502(TST x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (TSTshiftLL x0 y [c])
  1503(TST x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (TSTshiftRL x0 y [c])
  1504(TST x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (TSTshiftRA x0 y [c])
  1505(TST x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (TSTshiftRO x0 y [c])
  1506
  1507// prefer *const ops to *shift ops
  1508(ADDshiftLL (MOVDconst [c]) x [d]) => (ADDconst [c] (SLLconst <x.Type> x [d]))
  1509(ADDshiftRL (MOVDconst [c]) x [d]) => (ADDconst [c] (SRLconst <x.Type> x [d]))
  1510(ADDshiftRA (MOVDconst [c]) x [d]) => (ADDconst [c] (SRAconst <x.Type> x [d]))
  1511(ANDshiftLL (MOVDconst [c]) x [d]) => (ANDconst [c] (SLLconst <x.Type> x [d]))
  1512(ANDshiftRL (MOVDconst [c]) x [d]) => (ANDconst [c] (SRLconst <x.Type> x [d]))
  1513(ANDshiftRA (MOVDconst [c]) x [d]) => (ANDconst [c] (SRAconst <x.Type> x [d]))
  1514(ANDshiftRO (MOVDconst [c]) x [d]) => (ANDconst [c] (RORconst <x.Type> x [d]))
  1515(ORshiftLL  (MOVDconst [c]) x [d]) => (ORconst  [c] (SLLconst <x.Type> x [d]))
  1516(ORshiftRL  (MOVDconst [c]) x [d]) => (ORconst  [c] (SRLconst <x.Type> x [d]))
  1517(ORshiftRA  (MOVDconst [c]) x [d]) => (ORconst  [c] (SRAconst <x.Type> x [d]))
  1518(ORshiftRO  (MOVDconst [c]) x [d]) => (ORconst  [c] (RORconst <x.Type> x [d]))
  1519(XORshiftLL (MOVDconst [c]) x [d]) => (XORconst [c] (SLLconst <x.Type> x [d]))
  1520(XORshiftRL (MOVDconst [c]) x [d]) => (XORconst [c] (SRLconst <x.Type> x [d]))
  1521(XORshiftRA (MOVDconst [c]) x [d]) => (XORconst [c] (SRAconst <x.Type> x [d]))
  1522(XORshiftRO (MOVDconst [c]) x [d]) => (XORconst [c] (RORconst <x.Type> x [d]))
  1523(CMPshiftLL (MOVDconst [c]) x [d]) => (InvertFlags (CMPconst [c] (SLLconst <x.Type> x [d])))
  1524(CMPshiftRL (MOVDconst [c]) x [d]) => (InvertFlags (CMPconst [c] (SRLconst <x.Type> x [d])))
  1525(CMPshiftRA (MOVDconst [c]) x [d]) => (InvertFlags (CMPconst [c] (SRAconst <x.Type> x [d])))
  1526(CMNshiftLL (MOVDconst [c]) x [d]) => (CMNconst [c] (SLLconst <x.Type> x [d]))
  1527(CMNshiftRL (MOVDconst [c]) x [d]) => (CMNconst [c] (SRLconst <x.Type> x [d]))
  1528(CMNshiftRA (MOVDconst [c]) x [d]) => (CMNconst [c] (SRAconst <x.Type> x [d]))
  1529(TSTshiftLL (MOVDconst [c]) x [d]) => (TSTconst [c] (SLLconst <x.Type> x [d]))
  1530(TSTshiftRL (MOVDconst [c]) x [d]) => (TSTconst [c] (SRLconst <x.Type> x [d]))
  1531(TSTshiftRA (MOVDconst [c]) x [d]) => (TSTconst [c] (SRAconst <x.Type> x [d]))
  1532(TSTshiftRO (MOVDconst [c]) x [d]) => (TSTconst [c] (RORconst <x.Type> x [d]))
  1533
  1534// constant folding in *shift ops
  1535(MVNshiftLL (MOVDconst [c]) [d]) => (MOVDconst [^int64(uint64(c)<<uint64(d))])
  1536(MVNshiftRL (MOVDconst [c]) [d]) => (MOVDconst [^int64(uint64(c)>>uint64(d))])
  1537(MVNshiftRA (MOVDconst [c]) [d]) => (MOVDconst [^(c>>uint64(d))])
  1538(MVNshiftRO (MOVDconst [c]) [d]) => (MOVDconst [^rotateRight64(c, d)])
  1539(NEGshiftLL (MOVDconst [c]) [d]) => (MOVDconst [-int64(uint64(c)<<uint64(d))])
  1540(NEGshiftRL (MOVDconst [c]) [d]) => (MOVDconst [-int64(uint64(c)>>uint64(d))])
  1541(NEGshiftRA (MOVDconst [c]) [d]) => (MOVDconst [-(c>>uint64(d))])
  1542(ADDshiftLL x (MOVDconst [c]) [d]) => (ADDconst x [int64(uint64(c)<<uint64(d))])
  1543(ADDshiftRL x (MOVDconst [c]) [d]) => (ADDconst x [int64(uint64(c)>>uint64(d))])
  1544(ADDshiftRA x (MOVDconst [c]) [d]) => (ADDconst x [c>>uint64(d)])
  1545(SUBshiftLL x (MOVDconst [c]) [d]) => (SUBconst x [int64(uint64(c)<<uint64(d))])
  1546(SUBshiftRL x (MOVDconst [c]) [d]) => (SUBconst x [int64(uint64(c)>>uint64(d))])
  1547(SUBshiftRA x (MOVDconst [c]) [d]) => (SUBconst x [c>>uint64(d)])
  1548(ANDshiftLL x (MOVDconst [c]) [d]) => (ANDconst x [int64(uint64(c)<<uint64(d))])
  1549(ANDshiftRL x (MOVDconst [c]) [d]) => (ANDconst x [int64(uint64(c)>>uint64(d))])
  1550(ANDshiftRA x (MOVDconst [c]) [d]) => (ANDconst x [c>>uint64(d)])
  1551(ANDshiftRO x (MOVDconst [c]) [d]) => (ANDconst x [rotateRight64(c, d)])
  1552(ORshiftLL  x (MOVDconst [c]) [d]) => (ORconst  x [int64(uint64(c)<<uint64(d))])
  1553(ORshiftRL  x (MOVDconst [c]) [d]) => (ORconst  x [int64(uint64(c)>>uint64(d))])
  1554(ORshiftRA  x (MOVDconst [c]) [d]) => (ORconst  x [c>>uint64(d)])
  1555(ORshiftRO  x (MOVDconst [c]) [d]) => (ORconst  x [rotateRight64(c, d)])
  1556(XORshiftLL x (MOVDconst [c]) [d]) => (XORconst x [int64(uint64(c)<<uint64(d))])
  1557(XORshiftRL x (MOVDconst [c]) [d]) => (XORconst x [int64(uint64(c)>>uint64(d))])
  1558(XORshiftRA x (MOVDconst [c]) [d]) => (XORconst x [c>>uint64(d)])
  1559(XORshiftRO x (MOVDconst [c]) [d]) => (XORconst x [rotateRight64(c, d)])
  1560(BICshiftLL x (MOVDconst [c]) [d]) => (ANDconst x [^int64(uint64(c)<<uint64(d))])
  1561(BICshiftRL x (MOVDconst [c]) [d]) => (ANDconst x [^int64(uint64(c)>>uint64(d))])
  1562(BICshiftRA x (MOVDconst [c]) [d]) => (ANDconst x [^(c>>uint64(d))])
  1563(BICshiftRO x (MOVDconst [c]) [d]) => (ANDconst x [^rotateRight64(c, d)])
  1564(ORNshiftLL x (MOVDconst [c]) [d]) => (ORconst  x [^int64(uint64(c)<<uint64(d))])
  1565(ORNshiftRL x (MOVDconst [c]) [d]) => (ORconst  x [^int64(uint64(c)>>uint64(d))])
  1566(ORNshiftRA x (MOVDconst [c]) [d]) => (ORconst  x [^(c>>uint64(d))])
  1567(ORNshiftRO x (MOVDconst [c]) [d]) => (ORconst  x [^rotateRight64(c, d)])
  1568(EONshiftLL x (MOVDconst [c]) [d]) => (XORconst x [^int64(uint64(c)<<uint64(d))])
  1569(EONshiftRL x (MOVDconst [c]) [d]) => (XORconst x [^int64(uint64(c)>>uint64(d))])
  1570(EONshiftRA x (MOVDconst [c]) [d]) => (XORconst x [^(c>>uint64(d))])
  1571(EONshiftRO x (MOVDconst [c]) [d]) => (XORconst x [^rotateRight64(c, d)])
  1572(CMPshiftLL x (MOVDconst [c]) [d]) => (CMPconst x [int64(uint64(c)<<uint64(d))])
  1573(CMPshiftRL x (MOVDconst [c]) [d]) => (CMPconst x [int64(uint64(c)>>uint64(d))])
  1574(CMPshiftRA x (MOVDconst [c]) [d]) => (CMPconst x [c>>uint64(d)])
  1575(CMNshiftLL x (MOVDconst [c]) [d]) => (CMNconst x [int64(uint64(c)<<uint64(d))])
  1576(CMNshiftRL x (MOVDconst [c]) [d]) => (CMNconst x [int64(uint64(c)>>uint64(d))])
  1577(CMNshiftRA x (MOVDconst [c]) [d]) => (CMNconst x [c>>uint64(d)])
  1578(TSTshiftLL x (MOVDconst [c]) [d]) => (TSTconst x [int64(uint64(c)<<uint64(d))])
  1579(TSTshiftRL x (MOVDconst [c]) [d]) => (TSTconst x [int64(uint64(c)>>uint64(d))])
  1580(TSTshiftRA x (MOVDconst [c]) [d]) => (TSTconst x [c>>uint64(d)])
  1581(TSTshiftRO x (MOVDconst [c]) [d]) => (TSTconst x [rotateRight64(c, d)])
  1582
  1583// simplification with *shift ops
  1584(SUBshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [0])
  1585(SUBshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [0])
  1586(SUBshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [0])
  1587(ANDshiftLL y:(SLLconst x [c]) x [c]) => y
  1588(ANDshiftRL y:(SRLconst x [c]) x [c]) => y
  1589(ANDshiftRA y:(SRAconst x [c]) x [c]) => y
  1590(ANDshiftRO y:(RORconst x [c]) x [c]) => y
  1591(ORshiftLL  y:(SLLconst x [c]) x [c]) => y
  1592(ORshiftRL  y:(SRLconst x [c]) x [c]) => y
  1593(ORshiftRA  y:(SRAconst x [c]) x [c]) => y
  1594(ORshiftRO  y:(RORconst x [c]) x [c]) => y
  1595(XORshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [0])
  1596(XORshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [0])
  1597(XORshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [0])
  1598(XORshiftRO (RORconst x [c]) x [c]) => (MOVDconst [0])
  1599(BICshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [0])
  1600(BICshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [0])
  1601(BICshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [0])
  1602(BICshiftRO (RORconst x [c]) x [c]) => (MOVDconst [0])
  1603(EONshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [-1])
  1604(EONshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [-1])
  1605(EONshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [-1])
  1606(EONshiftRO (RORconst x [c]) x [c]) => (MOVDconst [-1])
  1607(ORNshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [-1])
  1608(ORNshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [-1])
  1609(ORNshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [-1])
  1610(ORNshiftRO (RORconst x [c]) x [c]) => (MOVDconst [-1])
  1611
  1612// rev16w | rev16
  1613// ((x>>8) | (x<<8)) => (REV16W x), the type of x is uint16, "|" can also be "^" or "+".
  1614((ADDshiftLL|ORshiftLL|XORshiftLL) <typ.UInt16> [8] (UBFX <typ.UInt16> [armBFAuxInt(8, 8)] x) x) => (REV16W x)
  1615
  1616// ((x & 0xff00ff00)>>8) | ((x & 0x00ff00ff)<<8), "|" can also be "^" or "+".
  1617((ADDshiftLL|ORshiftLL|XORshiftLL) [8] (UBFX [armBFAuxInt(8, 24)] (ANDconst [c1] x)) (ANDconst [c2] x))
  1618	&& uint32(c1) == 0xff00ff00 && uint32(c2) == 0x00ff00ff
  1619	=> (REV16W x)
  1620
  1621// ((x & 0xff00ff00ff00ff00)>>8) | ((x & 0x00ff00ff00ff00ff)<<8), "|" can also be "^" or "+".
  1622((ADDshiftLL|ORshiftLL|XORshiftLL) [8] (SRLconst [8] (ANDconst [c1] x)) (ANDconst [c2] x))
  1623	&& (uint64(c1) == 0xff00ff00ff00ff00 && uint64(c2) == 0x00ff00ff00ff00ff)
  1624	=> (REV16 x)
  1625
  1626// ((x & 0xff00ff00)>>8) | ((x & 0x00ff00ff)<<8), "|" can also be "^" or "+".
  1627((ADDshiftLL|ORshiftLL|XORshiftLL) [8] (SRLconst [8] (ANDconst [c1] x)) (ANDconst [c2] x))
  1628	&& (uint64(c1) == 0xff00ff00 && uint64(c2) == 0x00ff00ff)
  1629	=> (REV16 (ANDconst <x.Type> [0xffffffff] x))
  1630
  1631// Extract from reg pair
  1632(ADDshiftLL [c] (SRLconst x [64-c]) x2) => (EXTRconst [64-c] x2 x)
  1633( ORshiftLL [c] (SRLconst x [64-c]) x2) => (EXTRconst [64-c] x2 x)
  1634(XORshiftLL [c] (SRLconst x [64-c]) x2) => (EXTRconst [64-c] x2 x)
  1635
  1636(ADDshiftLL <t> [c] (UBFX [bfc] x) x2) && c < 32 && t.Size() == 4 && bfc == armBFAuxInt(32-c, c)
  1637	=> (EXTRWconst [32-c] x2 x)
  1638( ORshiftLL <t> [c] (UBFX [bfc] x) x2) && c < 32 && t.Size() == 4 && bfc == armBFAuxInt(32-c, c)
  1639	=> (EXTRWconst [32-c] x2 x)
  1640(XORshiftLL <t> [c] (UBFX [bfc] x) x2) && c < 32 && t.Size() == 4 && bfc == armBFAuxInt(32-c, c)
  1641	=> (EXTRWconst [32-c] x2 x)
  1642
  1643// Rewrite special pairs of shifts to AND.
  1644// On ARM64 the bitmask can fit into an instruction.
  1645(SRLconst [c] (SLLconst [c] x)) && 0 < c && c < 64 => (ANDconst [1<<uint(64-c)-1] x) // mask out high bits
  1646(SLLconst [c] (SRLconst [c] x)) && 0 < c && c < 64 => (ANDconst [^(1<<uint(c)-1)] x) // mask out low bits
  1647
  1648// Special case setting bit as 1. An example is math.Copysign(c,-1)
  1649(ORconst [c1] (ANDconst [c2] x)) && c2|c1 == ^0  => (ORconst [c1] x)
  1650
  1651// If the shift amount is larger than the datasize(32, 16, 8), we can optimize to constant 0.
  1652(MOVWUreg (SLLconst [lc] x)) && lc >= 32 => (MOVDconst [0])
  1653(MOVHUreg (SLLconst [lc] x)) && lc >= 16 => (MOVDconst [0])
  1654(MOVBUreg (SLLconst [lc] x)) && lc >= 8 => (MOVDconst [0])
  1655
  1656// After zero extension, the upper (64-datasize(32|16|8)) bits are zero, we can optimiza to constant 0.
  1657(SRLconst [rc] (MOVWUreg x)) && rc >= 32 => (MOVDconst [0])
  1658(SRLconst [rc] (MOVHUreg x)) && rc >= 16 => (MOVDconst [0])
  1659(SRLconst [rc] (MOVBUreg x)) && rc >= 8 => (MOVDconst [0])
  1660
  1661// bitfield ops
  1662
  1663// sbfiz
  1664// (x << lc) >> rc
  1665(SRAconst [rc] (SLLconst [lc] x)) && lc > rc => (SBFIZ [armBFAuxInt(lc-rc, 64-lc)] x)
  1666// int64(x << lc)
  1667(MOVWreg (SLLconst [lc] x)) && lc < 32 => (SBFIZ [armBFAuxInt(lc, 32-lc)] x)
  1668(MOVHreg (SLLconst [lc] x)) && lc < 16 => (SBFIZ [armBFAuxInt(lc, 16-lc)] x)
  1669(MOVBreg (SLLconst [lc] x)) && lc < 8  => (SBFIZ [armBFAuxInt(lc,  8-lc)] x)
  1670// int64(x) << lc
  1671(SLLconst [lc] (MOVWreg x))  => (SBFIZ [armBFAuxInt(lc, min(32, 64-lc))] x)
  1672(SLLconst [lc] (MOVHreg x))  => (SBFIZ [armBFAuxInt(lc, min(16, 64-lc))] x)
  1673(SLLconst [lc] (MOVBreg x))  => (SBFIZ [armBFAuxInt(lc, min(8,  64-lc))] x)
  1674
  1675// sbfx
  1676// (x << lc) >> rc
  1677(SRAconst [rc] (SLLconst [lc] x)) && lc <= rc => (SBFX [armBFAuxInt(rc-lc, 64-rc)] x)
  1678// int64(x) >> rc
  1679(SRAconst [rc] (MOVWreg x)) && rc < 32 => (SBFX [armBFAuxInt(rc, 32-rc)] x)
  1680(SRAconst [rc] (MOVHreg x)) && rc < 16 => (SBFX [armBFAuxInt(rc, 16-rc)] x)
  1681(SRAconst [rc] (MOVBreg x)) && rc < 8  => (SBFX [armBFAuxInt(rc,  8-rc)] x)
  1682// merge sbfx and sign-extension into sbfx
  1683(MOVWreg (SBFX [bfc] x)) && bfc.width() <= 32 => (SBFX [bfc] x)
  1684(MOVHreg (SBFX [bfc] x)) && bfc.width() <= 16 => (SBFX [bfc] x)
  1685(MOVBreg (SBFX [bfc] x)) && bfc.width() <=  8 => (SBFX [bfc] x)
  1686
  1687// sbfiz/sbfx combinations: merge shifts into bitfield ops
  1688(SRAconst [sc] (SBFIZ [bfc] x)) && sc < bfc.lsb()
  1689	=> (SBFIZ [armBFAuxInt(bfc.lsb()-sc, bfc.width())] x)
  1690(SRAconst [sc] (SBFIZ [bfc] x)) && sc >= bfc.lsb()
  1691	&& sc < bfc.lsb()+bfc.width()
  1692	=> (SBFX [armBFAuxInt(sc-bfc.lsb(), bfc.lsb()+bfc.width()-sc)] x)
  1693(SBFX [bfc] s:(SLLconst [sc] x))
  1694	&& s.Uses == 1
  1695	&& sc <= bfc.lsb()
  1696	=> (SBFX [armBFAuxInt(bfc.lsb() - sc, bfc.width())] x)
  1697(SBFX [bfc] s:(SLLconst [sc] x))
  1698	&& s.Uses == 1
  1699	&& sc > bfc.lsb()
  1700	=> (SBFIZ [armBFAuxInt(sc - bfc.lsb(), bfc.width() - (sc-bfc.lsb()))] x)
  1701
  1702// ubfiz
  1703// (x << lc) >> rc
  1704(SRLconst [rc] (SLLconst [lc] x)) && lc > rc => (UBFIZ [armBFAuxInt(lc-rc, 64-lc)] x)
  1705// uint64(x) << lc
  1706(SLLconst [lc] (MOVWUreg x))  => (UBFIZ [armBFAuxInt(lc, min(32, 64-lc))] x)
  1707(SLLconst [lc] (MOVHUreg x))  => (UBFIZ [armBFAuxInt(lc, min(16, 64-lc))] x)
  1708(SLLconst [lc] (MOVBUreg x))  => (UBFIZ [armBFAuxInt(lc, min(8,  64-lc))] x)
  1709// uint64(x << lc)
  1710(MOVWUreg (SLLconst [lc] x)) && lc < 32 => (UBFIZ [armBFAuxInt(lc, 32-lc)] x)
  1711(MOVHUreg (SLLconst [lc] x)) && lc < 16 => (UBFIZ [armBFAuxInt(lc, 16-lc)] x)
  1712(MOVBUreg (SLLconst [lc] x)) && lc < 8  => (UBFIZ [armBFAuxInt(lc,  8-lc)] x)
  1713
  1714// merge ANDconst into ubfiz
  1715// (x & ac) << sc
  1716(SLLconst [sc] (ANDconst [ac] x)) && isARM64BFMask(sc, ac, 0)
  1717	=> (UBFIZ [armBFAuxInt(sc, arm64BFWidth(ac, 0))] x)
  1718// (x << sc) & ac
  1719(ANDconst [ac] (SLLconst [sc] x)) && isARM64BFMask(sc, ac, sc)
  1720	=> (UBFIZ [armBFAuxInt(sc, arm64BFWidth(ac, sc))] x)
  1721
  1722// ubfx
  1723// (x << lc) >> rc
  1724(SRLconst [rc] (SLLconst [lc] x)) && lc < rc => (UBFX [armBFAuxInt(rc-lc, 64-rc)] x)
  1725// uint64(x) >> rc
  1726(SRLconst [rc] (MOVWUreg x)) && rc < 32 => (UBFX [armBFAuxInt(rc, 32-rc)] x)
  1727(SRLconst [rc] (MOVHUreg x)) && rc < 16 => (UBFX [armBFAuxInt(rc, 16-rc)] x)
  1728(SRLconst [rc] (MOVBUreg x)) && rc < 8  => (UBFX [armBFAuxInt(rc,  8-rc)] x)
  1729// uint64(x >> rc)
  1730(MOVWUreg (SRLconst [rc] x)) && rc < 32 => (UBFX [armBFAuxInt(rc, 32)] x)
  1731(MOVHUreg (SRLconst [rc] x)) && rc < 16 => (UBFX [armBFAuxInt(rc, 16)] x)
  1732(MOVBUreg (SRLconst [rc] x)) && rc < 8  => (UBFX [armBFAuxInt(rc,  8)] x)
  1733// merge ANDconst into ubfx
  1734// (x >> sc) & ac
  1735(ANDconst [ac] (SRLconst [sc] x)) && isARM64BFMask(sc, ac, 0)
  1736	=> (UBFX [armBFAuxInt(sc, arm64BFWidth(ac, 0))] x)
  1737// (x & ac) >> sc
  1738(SRLconst [sc] (ANDconst [ac] x)) && isARM64BFMask(sc, ac, sc)
  1739	=> (UBFX [armBFAuxInt(sc, arm64BFWidth(ac, sc))] x)
  1740// merge ANDconst and ubfx into ubfx
  1741(ANDconst [c] (UBFX [bfc] x)) && isARM64BFMask(0, c, 0) =>
  1742	(UBFX [armBFAuxInt(bfc.lsb(), min(bfc.width(), arm64BFWidth(c, 0)))] x)
  1743(UBFX [bfc] (ANDconst [c] x)) && isARM64BFMask(0, c, 0) && bfc.lsb() + bfc.width() <= arm64BFWidth(c, 0) =>
  1744	(UBFX [bfc] x)
  1745// merge ubfx and zero-extension into ubfx
  1746(MOVWUreg (UBFX [bfc] x)) && bfc.width() <= 32 => (UBFX [bfc] x)
  1747(MOVHUreg (UBFX [bfc] x)) && bfc.width() <= 16 => (UBFX [bfc] x)
  1748(MOVBUreg (UBFX [bfc] x)) && bfc.width() <=  8 => (UBFX [bfc] x)
  1749
  1750// Extracting bits from across a zero-extension boundary.
  1751(UBFX [bfc] e:(MOVWUreg x))
  1752	&& e.Uses == 1
  1753	&& bfc.lsb() < 32
  1754	=> (UBFX [armBFAuxInt(bfc.lsb(), min(bfc.width(), 32-bfc.lsb()))] x)
  1755(UBFX [bfc] e:(MOVHUreg x))
  1756	&& e.Uses == 1
  1757	&& bfc.lsb() < 16
  1758	=> (UBFX [armBFAuxInt(bfc.lsb(), min(bfc.width(), 16-bfc.lsb()))] x)
  1759(UBFX [bfc] e:(MOVBUreg x))
  1760	&& e.Uses == 1
  1761	&& bfc.lsb() < 8
  1762	=> (UBFX [armBFAuxInt(bfc.lsb(), min(bfc.width(), 8-bfc.lsb()))] x)
  1763
  1764// ubfiz/ubfx combinations: merge shifts into bitfield ops
  1765(SRLconst [sc] (UBFX [bfc] x)) && sc < bfc.width()
  1766	=> (UBFX [armBFAuxInt(bfc.lsb()+sc, bfc.width()-sc)] x)
  1767(UBFX [bfc] (SRLconst [sc] x)) && sc+bfc.width()+bfc.lsb() < 64
  1768	=> (UBFX [armBFAuxInt(bfc.lsb()+sc, bfc.width())] x)
  1769(SLLconst [sc] (UBFIZ [bfc] x)) && sc+bfc.width()+bfc.lsb() < 64
  1770	=> (UBFIZ [armBFAuxInt(bfc.lsb()+sc, bfc.width())] x)
  1771(UBFIZ [bfc] (SLLconst [sc] x)) && sc < bfc.width()
  1772	=> (UBFIZ [armBFAuxInt(bfc.lsb()+sc, bfc.width()-sc)] x)
  1773// ((x << c1) >> c2) >> c3
  1774(SRLconst [sc] (UBFIZ [bfc] x)) && sc == bfc.lsb()
  1775	=> (ANDconst [1<<uint(bfc.width())-1] x)
  1776(SRLconst [sc] (UBFIZ [bfc] x)) && sc < bfc.lsb()
  1777	=> (UBFIZ [armBFAuxInt(bfc.lsb()-sc, bfc.width())] x)
  1778(SRLconst [sc] (UBFIZ [bfc] x)) && sc > bfc.lsb()
  1779	&& sc < bfc.lsb()+bfc.width()
  1780	=> (UBFX [armBFAuxInt(sc-bfc.lsb(), bfc.lsb()+bfc.width()-sc)] x)
  1781// ((x << c1) << c2) >> c3
  1782(UBFX [bfc] (SLLconst [sc] x)) && sc == bfc.lsb()
  1783	=> (ANDconst [1<<uint(bfc.width())-1] x)
  1784(UBFX [bfc] (SLLconst [sc] x)) && sc < bfc.lsb()
  1785	=> (UBFX [armBFAuxInt(bfc.lsb()-sc, bfc.width())] x)
  1786(UBFX [bfc] (SLLconst [sc] x)) && sc > bfc.lsb()
  1787	&& sc < bfc.lsb()+bfc.width()
  1788	=> (UBFIZ [armBFAuxInt(sc-bfc.lsb(), bfc.lsb()+bfc.width()-sc)] x)
  1789
  1790// bfi
  1791(OR (UBFIZ [bfc] x) (ANDconst [ac] y))
  1792	&& ac == ^((1<<uint(bfc.width())-1) << uint(bfc.lsb()))
  1793	=> (BFI [bfc] y x)
  1794(ORshiftLL [s] (ANDconst [xc] x) (ANDconst [yc] y))
  1795	&& xc == ^(yc << s)    // opposite masks
  1796	&& yc & (yc+1) == 0    // power of 2 minus 1
  1797	&& yc > 0              // not 0, not all 64 bits (there are better rewrites in that case)
  1798	&& s+log64(yc+1) <= 64 // shifted mask doesn't overflow
  1799	=> (BFI [armBFAuxInt(s, log64(yc+1))] x y)
  1800(ORshiftRL [rc] (ANDconst [ac] x) (SLLconst [lc] y))
  1801	&& lc > rc && ac == ^((1<<uint(64-lc)-1) << uint64(lc-rc))
  1802	=> (BFI [armBFAuxInt(lc-rc, 64-lc)] x y)
  1803// bfxil
  1804(OR (UBFX [bfc] x) (ANDconst [ac] y)) && ac == ^(1<<uint(bfc.width())-1)
  1805	=> (BFXIL [bfc] y x)
  1806(ORshiftLL [sc] (UBFX [bfc] x) (SRLconst [sc] y)) && sc == bfc.width()
  1807	=> (BFXIL [bfc] y x)
  1808(ORshiftRL [rc] (ANDconst [ac] y) (SLLconst [lc] x)) && lc < rc && ac == ^((1<<uint(64-rc)-1))
  1809	=> (BFXIL [armBFAuxInt(rc-lc, 64-rc)] y x)
  1810
  1811// FP simplification
  1812(FNEGS  (FMULS  x y)) => (FNMULS x y)
  1813(FNEGD  (FMULD  x y)) => (FNMULD x y)
  1814(FMULS  (FNEGS  x) y) => (FNMULS x y)
  1815(FMULD  (FNEGD  x) y) => (FNMULD x y)
  1816(FNEGS  (FNMULS x y)) => (FMULS  x y)
  1817(FNEGD  (FNMULD x y)) => (FMULD  x y)
  1818(FNMULS (FNEGS  x) y) => (FMULS  x y)
  1819(FNMULD (FNEGD  x) y) => (FMULD  x y)
  1820
  1821(FADDS a (FMULS  x y)) && a.Block.Func.useFMA(v) => (FMADDS  a x y)
  1822(FADDD a (FMULD  x y)) && a.Block.Func.useFMA(v) => (FMADDD  a x y)
  1823(FSUBS a (FMULS  x y)) && a.Block.Func.useFMA(v) => (FMSUBS  a x y)
  1824(FSUBD a (FMULD  x y)) && a.Block.Func.useFMA(v) => (FMSUBD  a x y)
  1825(FSUBS (FMULS  x y) a) && a.Block.Func.useFMA(v) => (FNMSUBS a x y)
  1826(FSUBD (FMULD  x y) a) && a.Block.Func.useFMA(v) => (FNMSUBD a x y)
  1827(FADDS a (FNMULS x y)) && a.Block.Func.useFMA(v) => (FMSUBS  a x y)
  1828(FADDD a (FNMULD x y)) && a.Block.Func.useFMA(v) => (FMSUBD  a x y)
  1829(FSUBS a (FNMULS x y)) && a.Block.Func.useFMA(v) => (FMADDS  a x y)
  1830(FSUBD a (FNMULD x y)) && a.Block.Func.useFMA(v) => (FMADDD  a x y)
  1831(FSUBS (FNMULS x y) a) && a.Block.Func.useFMA(v) => (FNMADDS a x y)
  1832(FSUBD (FNMULD x y) a) && a.Block.Func.useFMA(v) => (FNMADDD a x y)
  1833
  1834(MOVBUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read8(sym, int64(off)))])
  1835(MOVHUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read16(sym, int64(off), config.ctxt.Arch.ByteOrder))])
  1836(MOVWUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read32(sym, int64(off), config.ctxt.Arch.ByteOrder))])
  1837(MOVDload  [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read64(sym, int64(off), config.ctxt.Arch.ByteOrder))])
  1838(MOVBload  [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(int8(read8(sym, int64(off))))])
  1839(MOVHload  [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(int16(read16(sym, int64(off), config.ctxt.Arch.ByteOrder)))])
  1840(MOVWload  [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(int32(read32(sym, int64(off), config.ctxt.Arch.ByteOrder)))])
  1841
  1842// Prefetch instructions (aux is option: 0 - PLDL1KEEP; 1 - PLDL1STRM)
  1843(PrefetchCache addr mem)         => (PRFM [0] addr mem)
  1844(PrefetchCacheStreamed addr mem) => (PRFM [1] addr mem)
  1845
  1846// Arch-specific inlining for small or disjoint runtime.memmove
  1847(SelectN [0] call:(CALLstatic {sym} s1:(MOVDstore _ (MOVDconst [sz]) s2:(MOVDstore  _ src s3:(MOVDstore {t} _ dst mem)))))
  1848	&& sz >= 0
  1849	&& isSameCall(sym, "runtime.memmove")
  1850	&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
  1851	&& isInlinableMemmove(dst, src, sz, config)
  1852	&& clobber(s1, s2, s3, call)
  1853	=> (Move [sz] dst src mem)
  1854
  1855// Match post-lowering calls, register version.
  1856(SelectN [0] call:(CALLstatic {sym} dst src (MOVDconst [sz]) mem))
  1857	&& sz >= 0
  1858	&& isSameCall(sym, "runtime.memmove")
  1859	&& call.Uses == 1
  1860	&& isInlinableMemmove(dst, src, sz, config)
  1861	&& clobber(call)
  1862	=> (Move [sz] dst src mem)
  1863
  1864((REV|REVW) ((REV|REVW) p)) => p
  1865
  1866// internal/runtime/math.MulUintptr intrinsics
  1867
  1868(Select0 (Mul64uover x y)) => (MUL x y)
  1869(Select1 (Mul64uover x y)) => (NotEqual (CMPconst (UMULH <typ.UInt64> x y) [0]))

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